I thinks it's really your preference no two vibrants are the same so whatever works best for your phone and for you is what matters try them both try them all you'll figure out what's best for you I'm running bionix final with jacs oc/uv kernel but I've tried the froyo roms they are cool but for me this works best have fun and for the love of god stay drunk
Times never wasted when your getting waisted
Fair question, but somewhat irrelevant in my opinion. My experience with stock vs cooked ROMs (MT3G CM6) is that the only real advantage is better speed. Sure, a few different user-experience changes, but that's all. An the stock ROMs are far more stable.
My stock Vibrant is already plenty fast. I'm rooted and can use root-only apps. My Dolphin browser already displays Flash. JIT will make it technically faster, but will I actually notice..? What would Eugene or TeamWhiskey add to that...?