I liked Pain and Gain, but do recognize it's not for everyone.
That movie was a great display of the snowball effect. It starts small and just a little weird, and by the end of the movie the stupidity has gone far into overdrive.
I'd say it's worth a watch just to see how crazy it gets. Note: the movie is supposed to be an account of stuff that actually happened from what I understand, not just "based" on actual events. So if you're judging actors/directors on this movie you have to include that caveat to keep things fair.
I like Marky Mark, I think he does good movies. But I can also understand why some people wouldn't, he does go a bit overboard sometimes.
The Rock gets pretty nutz in that movie, too. If you want to see Rock portraying a muscular cokehead, then watch that movie or just find him and give him coke in real life. The movie is probably a better idea, but the latter option would be much more memorable.