Like most I earned my certification in a jacket style BCD. I also did my first 50 or so dives (10 years ago) in different jacket style BCDs. When I purchased my first BCD in 1995, it was custom made DuraPro SlimLine 385 Tech (weight integrated). I dove it almost exclusively up until 2002. I did experient with other people's BCDs, both jacket and back inflate styles during that time but only to try them out for two or three dives. In 2002, the good ol' SlimLine was showing some wear, albeit minor, and I decided an OMS IQ Pack w/AL backplate and a 45# single bladder wing was a good replacement. In early 2004 I replaced the IQ pack with an OMS Comfort Harness. I've also added the 32# single tank wing to my collection.
All that experience has lead me to concur with Chris... a good diver is a good diver and can make do with most any equipment. I do find myself tremendously more comfortable in back inflates than jacket style BCDs - beit for fit, unclutteredness or perhaps simply experience, but have a hard time saying I'm more comfortable in a BP&W vs a back inflate. I do feel as though I am able to fine tune my trim much more acutely with a BP & W than simply a back inflate.
I have the most difficutly identifying differences in hydrodynamics/stability of different sized wings. Having dove a DuraPro/AmerSea's 75# Expando wing, Zeagle Ranger w/44# wing (I think it was 44#), Dive Rite's Travel and Venture Wings, OMS 45# and 32# wing all with single tanks I can't tell you that one feels more hydrodynamic/stable than the other underwater. I contribute this to the fact that I believe I am properly weighted and have pretty good buoyancy control, allowing me to dive with very minimal air in my wing.