I always preferred bare metal. Yes, cleanup is a factor. But more than that is the feel. I want to be able to easily shift my hand position along the shaft for mechanical/leverage advantage and to sometimes bypass obstructions by shifting my knuckles to a different spot. The rubberized or plastic contour handles almost force you to grasp them in the position the mfr determined you should be holding it. There's something in my 'muscle memory' that resents that. They feel like they're almost in the way of my grasping the ratchet, kind of awkward. I'm a bit of an old-timer so habit and tradition probably plays a role in this.
My favorite rats are the old New Britain RHFT Kilness design with the round knurled handles, followed by the similar S-K, but the Kilness has a more compact and lighter head so it fits in tighter places, is less clunky and better balanced.
Least favorite of all the major brand names I've handled is the Craftsman raised panel handles. Ugh. Come to think of it, I never liked anything about the CM RP rats. Something about them almost seems like an imitation or impostor ratchet, like the 'plus opening act' band at a concert. Yeah, it's a band, it plays, there's music to listen to, but.... It's purely subjective and ambiguous, I know.
There's something very **** and seductive about the Cornwell bare steel 'coke bottle' handles. Perhaps the best-of-all-worlds design. But when it's time to get down and dirty, I still grab the Kilness rats. Go figure.