Both Leinster and Munster have yet to taste defeat so far this season. And with the two teams expected to be at near full strength and selection for the autumn internationals just around the corner, it is no wonder that Sunday's sold-out clash is being hyped up so much.
Doffing his cap to the efforts of McGahan and company, Cheika spoke at Tuesday's Leinster press conference of his admiration for Munster and their early season efforts.
He said: "Munster have looked very good. They have definitely benefited from having all their player available from day one and they've returned 14 from 15 points so that pretty much says it all really.
"I think that they're an improving team. They have a lot more clarity about how they want to play their wide game and they do it well because they have some great finishers.
"(Doug) Howlett has really been in excellent form, trailing behind the back and in his work off the ball. I think that their coach (Tony McGahan) has been very clever in the way he has used his squad.
"He has given himself a really good choice to select from, so I've been pretty impressed by what he has done so far."
Cheika's lot have also not been slow off the blocks. A gritty draw away to Cardiff was followed by home wins over Edinburgh (with a bonus point) and the Ospreys.
Last weekend's 19-13 defeat of the Ospreys came at a cost as utility back Isa Nacewa sustained a broken arm during the latter stages of the game. Nacewa played through the pain barrier to slot two vital drop goals.
Cheika commented: "He thinks he did it (broken arm) before the second drop goal last weekend. I'm not sure if he was even aware of the injury to be honest at the time.
"Even when he walked off the field he was holding his arm and said to me, 'I think I've broken my arm.'
"I'm not sure if it was purely adrenaline, but it was unfortunate that it happened and you can't control that part of the game."
Nacewa's absence for this week's provincial derby should open the way for Jonathan Sexton's return to the out-half berth, although there is also the possibility of Felipe Contepomi moving to number 10 and the in-form Luke Fitzgerald partnering Brian O'Driscoll in midfield.
'We would have liked to have tried Luke (Fitzgerald) at centre before now, but we'll see how things are after training today (Tuesday) and tomorrow (Wednesday) and go from there," added the Leinster boss.
"Rob Kearney always has a chance of playing full-back. He's a quality player but it's testament to how well Girvan Dempsey has been playing.
'We have to make difficult selections every week when it comes down to the back-three."
Two big-hitters from the Southern Hemisphere are in line to make their debuts for Leinster this weekend and Cheika conceded that the arrivals of Springbok prop CJ Van Der Linde and Australian back rower Rocky Elsom have provided a boost to his squad.
"It's always good to get your full squad together. We have close to a full deck to choose from in the forwards. It's slightly different in the backs (with Nacewa and Gordon D'Arcy injured), so we're going to have to make some decisions.
"Rocky (Elsom) has had an interrupted Tri Nations because he had one week off with an injury, but there seems to be quite big gaps in this format where teams played three games and then had a break.
"CJ (Van Der Linde) has obviously had a bit of a break, so he should be fresh! We'll just see how training goes.
"If anything the break would have been good for them both. I think they're very keen to play from what I've seen of the two of them.
"They're obviously quality players and they have a lot of experience and that will be an asset as well when you apart from the physical presence that they will bring.
"I think that what you'll see with Rocky is that he is a power player, a good lineout operator and a good defender. The main thing is that they'll need to adjust their game because there are differences in the Northern Hemisphere.
"CJ is an excellent scrummager and a very dynamic player as well being able to play both sides of the scrum, as can Stan (Wright), which means that there's good versatility in all our props.
"There's Stephen (Knoop) and Cian Healy and Ronnie (McCormack) can also play tight and loosehead.
"We are looking at trying to improve every game. We've had a mix of front rows and second rows so we're going to try and find the best formula going forward."