It's certainly not the best of the bunch - I think that award will always belong to Big for me personally, but it's a lot better than I thought it would be and I was surprised at how good Zac Effron was too. I've never really paid him much attention before, being in my late 20's I'm not really in the target audience for his previous offerings! He's a surprisingly good actor and what I was particularly impressed by was how he nailed Matthew Perry's mannerisms and speech style and fed them into his portrayal of 'Young Mike'. Very Clever.
Matthew Perry was actually slightly miscast in this I thought, but unfortunately, I think the ghost of Chandler Bing will follow him throughout his career and he may seem out of place no matter what he does.
The storyline has a few whopping holes in it - I spent half the movie trying to work out how Scarlett supposedly fell pregnant in '89, yet 20 years later her child was still in High School? Never mind though, it was a perfectly reasonable piece of fluff to while away a couple of hours and sometimes you don't need to look any deeper than that!