If by carve you mean "curve" i.e. fingerboard radius, I personally have found flatter to be more comfortable to me. My old Gibson EB3-L with a 12" radius (I believe it was 12") and My SX Ursa 1 with a 15" radius were two of the most comfortable basses I've ever played. YMMV, of course.
You can call me ...Cliff.
"If I could walk that way, I wouldn't need the talcum powder."