The traditional Christmas interprovincial programme finds one of the combatants in scintillating form, one in the midst of crisis, while the other two have experienced a resurgence after sluggish openings to the campaign.
The underwhelming European fare led Gordon D'Arcy to argue this week that the Champions Cup is a "shell of what it once was", with so many teams writing off the competition early to prioritise domestic concerns.
Gloucester's decision to ape Mick McCarthy at Old Trafford circa 2010 by picking a weakened team for their away game against Leinster was surely a damaging moment for club rugby's blue riband event.
In that context, the upcoming interpro fare is much welcomed, with the Munster-Leinster showdown on St Stephen's Day already sold out.
TV
Connacht v Ulster (Friday, 7.35pm) is live on RTÉ2 and RTÉ Player, with Munster v Leinster (Monday, 7.35pm) live on TG4 and Premier Sports 2.
All games are live on URC TV.
RADIO
RTÉ Radio 1 will have live commentary of both Connacht v Ulster and Munster v Leinster.
ONLINE
Follow our live blogs on rte.ie/sport and the RTÉ News app with match reports and reaction from around the grounds.
WEATHER
There is the chance of some heavy rain in Galway on Friday afternoon but that should gradually clear northwards prior to kick-off, although there is still the chance of a few showers during the game. It will be a mild evening, with temperatures of around 10C forecast in moderate easterly winds.
Temperatures could drop to 5C at Thomond Park on St Stephen's Day, although it is at least expected to be dry after scattered showers in the afternoon.
It's hard to conceive of how December could have gone much worse for Ulster. They began the month by surrendering a 19-point lead against 14 men in the RDS.
A week later, they were held scoreless in a horror show away to Sale, a performance probably not helped by their being forced to fly over to different airports in England on the morning of the game.
Their logistical travails were only just getting started. The following weekend, a series of unfortunate events saw their win-or-bust European tie against reigning champions La Rochelle played behind closed doors in the Aviva Stadium.
The only faction in the 'crowd' was what was termed a "large official delegation" from the French club.
At half-time last Saturday evening, as the grunting and heaving from the pitch could be heard echoing around a sadly empty Lansdowne Road, it felt to all watching at home that their season had utterly imploded.
In a sign that Ulster's discipline had gone the way of their logistical planning, Antoine Hastoy slammed over five penalties in the opening half. The out-half added a drop-goal and scored a try for good measure. Brice Dulin was the only other player to score as Ronan O'Gara's side ran up a 29-0 lead by the break. In just over four halves of rugby, Ulster had conceded 103 points and scored seven.
From the depths of despair, there was a stirring rally. Incredibly, the 'hosts' (sort of) almost rescued a draw, tries from Iain Henderson, who was sin-binned in the first half, John Cooney, Duane Vermuelen and Tom Stewart bringing the score back to a highly respectable 36-29 in the finish. Could that second half reignite their season?
Connacht, form, meanwhile, has been going in the opposite direction, with six wins from their last eight after a sluggish start to the season.
Highlights include the 20-11 win over Munster in the Sportsground, and the back-to-back wins over Welsh opposition, at home to Scarlets and away to Ospreys, in late October. Meanwhile, they're three from three in December, with a URC win over Benneton followed by Challenge Cup triumphs over Newcastle Falcons and Brive.
Head coach Pete Wilkins was quick to reinterpret Ulster's recent struggles in a more benign light and insisted there would be no complacency among his charges.
"There's obviously been a fair amount of narrative around things off the field that have added to their story of the last three games.
"The other thing to recognise is that they've been playing three really good teams in Leinster, Sale and La Rochelle, so you don't come under pressure by accident, they've been up against some pretty tough opposition.
"We have to acknowledge that as well and there's certainly no complacency on our end."
The win over Brive came at a cost with lock Gavin Thornbury bound for a prolonged period on the sidelines, incurring a knee injury following a relatively innocuous tackle from Tietie Tuimauga. The 29-year old will require surgery and Wilkins described the injury as "serious."
Connacht: Tiernan O'Halloran; John Porch, Tom Farrell, Bundee Aki, Mack Hansen; Jack Carty (capt), Caolin Blade; Denis Buckley, Shane Delahunt, Finlay Bealham; Josh Murphy, Niall Murray; Oisín Dowling, Conor Oliver, Cian Prendergast.
Replacements: Dave Heffernan, Peter Dooley, Dominic Robertson-McCoy, Shamus Hurley-Langton, Jarrad Butler, Kieran Marmion, David Hawkshaw, Adam Byrne.
Ulster: Mike Lowry; Ethan McIlroy, Luke Marshall, Stuart McCloskey, Rob Lyttle; Nathan Doak, John Cooney; Rory Sutherland, Tom Stewart, Marty Moore; Alan O’Connor, Iain Henderson (capt), David McCann, Marcus Rea, Nick Timoney.
Replacements: John Andrew, Eric O’Sullivan, Gareth Milasinovich, Sam Carter, Greg Jones, Dave Shanahan, Jake Flannery, Stewart Moore.
Referee: Frank Murphy (IRFU).
The mood has altered at Thomond Park since Munster's 27-13 loss to Leinster a couple of months back.
Back then, the squad was afflicted with injury problems and were in the early stages of adapting to their more expansive gameplan under the recently-installed coaching ticket.
That was followed by a narrow loss at home to Ulster and fatalists might have sighed that Munster were set for a grim year of transition.
Since then, the weather has broken a little, and they've won four of their next five, two in the URC, one in Europe and the other being the rousing victory over South Africa 'A' in Páirc Uí Chaoimh.
The Champions Cup window strengthened the notion that their game is coming together, with a highly competitive showing against five-time champions Toulouse in the Limerick fog and then a hard-fought victory over Northampton at Franklin Gardens.
The Munster support have been patient, willing to offer Graham Rowntree and Mike Prendergast time to put their stamp on the team after a couple of seasons of frustrating stasis under their predecessors.
Speaking to RTÉ Sport this week, Prendergast said the team has evolved since their 14-point reversal in the Aviva in October.
"As we alluded to as a coaching staff from the start, it was always going to take a bit of time. We are still on that journey. Week on week, month on month, we have improved in different domains, parts of our game.
"When you look at that now, two months ago to now, our ability to move quicker on both sides of the ball is something that's coming through."
The visitors' form is as imperious as ever. Already nine from nine in the URC and nine points clear in the table, they proceeded to smash their 2018 final opponents Racing 92 in a statement victory in Paris. Then last weekend, Gloucester saw fit to write off their trip to the RDS as a hopeless task.
One senses there is an added impetus this weekend after the manner in which the last campaign finished, with sickening failure on both fronts, particularly in the Champions Cup final defeat to La Rochelle.
The Thomond Park hoodoo is an ancient memory - Leinster's 2010 victory in Limerick was their first in 15 years - and Leo Cullen's side have won nine of the last 10 games against Munster, the only defeat arriving in the long-forgotten Rainbow Cup.
Stuart Lancaster, however, warned this week that Munster are an extremely different proposition to two months ago, extolling the evolution in their attacking game.
"It's a completely different style to 18 months ago, isn’t it? You were pretty much guaranteed a box kick would come first as an exit policy.
"Now it’s a box kick but it could easily be a mindset to run as well so there has definitely been an evolution.
"That’s the type of thing we have talked about in the preview because it would be pretty naïve to think that they are not confident now - because they should be."
Munster: Shane Daly, Calvin Nash, Antoine Frisch, Jack Crowley, Keith Earls, Joey Carbery, Conor Murray, Dave Kilcoyne, Niall Scannell, John Ryan, Jean Kleyn, Tadhg Beirne, Jack O'Donoghue, Peter O'Mahony, Gavin Coombes.
Replacements: Diarmuid Barron, Josh Wycherley, Roman Salanoa, Kiran McDonald, Alex Kendellen, Craig Casey, Rory Scannell, Patrick Campbell.
Leinster: Hugo Keenan, Jordan Larmour, Garry Ringrose, Jamie Osborne, James Lowe, Ross Byrne, Nick McCarthy, Andrew Porter, Dan Sheehan, Cian Healy, Ryan Baird, Joe McCarthy, Rhys Ruddock, Scott Penny, Max Deegan.
Replacements: John McKee, Michael Milne, Vakhtang Abdaladze, Ross Molony, Jack Conan, Luke McGrath, Harry Byrne, Liam Turner.
Referee: Chris Busby (IRFU).
Listen to live commentary of Munster v Leinster (26 December, 7.35pm) and Connacht v Ulster (23 December, 7.35pm) on RTÉ Radio 1, or follow our live blogs on rte.ie/sport and the RTÉ News app.
Watch live coverage of Connacht v Ulster on RTÉ2 and RTÉ Player.
