It's a heist movie. Sure, the idea's not original, and you can predict roughly what's going to happen as soon as you meet the players; but it's still good fun.
There are very few big-name stars, which helps a great deal - if you see Bruce or Mel, you know he's going to come out on top, and here there's just a little bit of doubt.
I was repeatedly reminded of The Italian Job - particularly in the "you're only supposed to blow the bloody doors off" scene (it doesn't use that line, but you'll know the scene when you get to it); it's a shame that this didn't get the publicity that the remake of that film did, as I found it much more enjoyable.
The special effects aren't bad. They're not hugely flashy as on films with bigger budgets, but they do the job; most of the action takes place at night, which certainly helps with the bluescreening. The technicalities are a bit iffy, but not as wildly implausible as usual for Hollywood; they may actually have got a competent technical advisor on this one.
Not an intellectually engaging movie, but a good choice for a relaxed evening in.