Simply from my observations, and not from any theoretical standpoint, if you'll be doing a lot of manuvering (in and out of slips, narrow channels, etc) a fin would be better. If you're passagemaking then the full would seem to work better. That though, is simply my opinion.
Currently at 34 12 22 N 77 48 01 W, Wrightsville Beach, NC
It's my opinion as well. Maneuvering in tight spaces under power is definitely clumsier with my pilothouse cutter, but I attribute this in part to my windage. Part of this is being addressed via the installation of a four-bladed feathering prop, which will be pitched in reverse to provide considerably more stopping power and less prop walk. The other way to address this is to go back to older methods of maneuvering in tight places via the use of spring lines and warping off the dock or wall. On moorings, you sometimes get better results sailing off than motoring, or by using a combination.
It's best practised on a sea wall with little else around at first, but warping can put the bow where you want it even in contrary winds, but like heaving-to and knowing when to reef, it takes real practice and every boat is different. In my case, I have to dock "blind" as I can't see the dock from the pilothouse, and I have to make sure I don't clip the davits of my neighbour (I have a slip at the end of a finger.) This is when a good set of fenders, some skill at aiming, and the faith in going into neutral and trusting inertia to keep you moving comes into play. My wife is no long-jumper, but she hasn't got herself or the mid-ship spring line wet yet.