Hi Water Baby
I recently bought the SeaQuest EVA, which is the basically the cheaper version of the DIVA. I love the functionality, i.e. pockets, handle, integrated weight system, padding at the back etc. The BCD is really comfortable and it fit me perfectly in the store, so I bought it. However, when I wore it diving for the first time I was a bit taken back as it was became too loose. The integrated weight system pulled the pockets out and away from my body. I needed twice as much weight as usual because I was diving in the Red Sea (the most buoyant water in the world after the dead sea) in a 7mm wet suit with a 12 litre aluminium tank on my back. To compensate for the pull from the extra weight, I had the BCD adjusted at the tightest waist setting, but it was still too loose at the front when swimming. Mind you, in standing position it was absolutely fine. In order the get streamlined, I ended up diving with my arms crossed at my waist to keep the pockets down and the BCD snug.
The moral of this story is if you have the chance to try the BCD in water before making a purchase - take it. A great fit above water even with full gear on, doesnt necessarily equate a great fit under water. Unfortunately not many stores offer the opportunity to test equipment before purchase, but perhaps its worth making an effort to find a store that does. After all, the BCDs that you're considering are not cheap, so you should be pleased with your purchase for years to come. In my case, I just hope that the problem wont be so bad if I go diving in different conditions requiring less weight. I've only made 20 dives with the BCD and aside from what I've just mentioned I am satisfied with it.
Happy Shopping
Sylvie