I didn't have any problems with the Balance, but if you are set on looking at the jacket BC's, I would choose the ProQD+ over the Unlimited. The Pro Unlimited adds a few things, but not worth the extra price IMO.
The difference between the Unlimited and the ProQD+ : a knife, a cummerbund pocket, integrated retractor, adjustable chest strap, and the rear pull dump handle is routed to the front instead of being at the back. It also has the self-adjusting lumbar support. Except for the knife, I think they are all bells and whistles that you can do without, and hardly worth the extra $350. (And you can buy the knife for $40 and attach it the same way, as all Seaquest BC's have the attachment holes for the rivets.)