Just a counter-opinion to some of these here: I used a non-integrated US Divers BC and weight belt before and had the buckle come loose, losing the belt and all the weights in seconds. I have narrow hips and also had a problem with the belt sliding around and down. I swore then I would get an integrated weight system with my next purchase and have never looked back, very happy with my ProQD.
Either weight system can be lost, and given that weights are, well... heavy, it always behooves one to ensure whatever weight system you're using is very secure before jumping in. But if you accidentally lose your lead, with an integrated system you will most likely only lose one pocket, not all your ballast in one dump like with a belt.
I know the integrated vs. non-integrated weight thing is one of those never-ending debates here on SB like snorkel vs. no snorkel / splits vs. paddles / pony vs. ponyless / computer vs. tables / AI vs. non-AI / BC vs. BPW / integrated second vs. octo, and on and on and on... But both sides deserve to be heard and traditional weight belts just don't work for some of us (nor traditional tables, nor traditional fins, nor traditional SPG's, etc... I guess I'm just a non-traditional kind of guy).
>*< Fritz