The vest works pretty well especially for the price, but these things annoy me:
1. The little weights are a bit of a pain to get in their slots. If you wanted to add or remove a bunch of them, it would take awhile. The weights often don't fit that well, either, and the flaps that are supposed to cover them don't work very well. It seems like they cut corners in the design or manufacture.
2. Because of the above, the weights sometimes fall out. Pick it up wrong, and half of them could end up on the floor.
3. The velcro flaps that are supposed to fold over your chest and keep the font and back together aren't that strong. If you do a motion like a pull-up, it might open up on you. For certain exercises, such as one where the weight of the front portion lays against the flaps, nothing I can do will keep them together. This may have something to do with my shape, since I'm pretty thin.
Overall, I'd give this 3.5 stars. With a better design of the flaps and velcro, it would be 5!
EDIT: I took a closer look in a brighter room, and if you're careful to make sure the flaps are over the weights, the problem of bags flying out shouldn't be so bad. It takes a little more time, but it's worth it. I still think there has to be a better design, but to be fair, items 1 and 2 aren't as annoying as I portrayed, so I bumped this up to 4 stars.