I like the weight integration in my new ProQD so far(but it only has 2 dives on it)
Just one less thing to put on, take off, keep track of on boat or shore. I have been looking at various systems of weight integration since I started diving in '78, and I like what my QD delivers. Nothing wrong with belts, they work fine, just like horsecollar bc's, just take a bit more time to get on and off and more effort to keep track of IMAO.
I have dove with old school equipment and new school, including BP/W's, all have their place and adherants. I prefer Jacket BC's with weight integration and knife attached for my diving, but everyone has different preferences that suit the diving they like to do. It is easy enough to rent a weight integrated BC nowadays if you can't find someone who will let you try a quick dive in theirs, so try it and see if you like it.
When diving out of buddies zodiac, we remove equipment in water then board and pull it in, with weight integrated BC the process is much less complicated and I don't have to worry about dropping the weight belt when removing it and putting it aboard prior to removing bc and tank. Also use the same procedure when diving out of friends boats with less than substantial ladders.