I really have no preference for either of the two cameras, because in my opinion they both have equal amounts of good aspects about them, as well as bad things. As far as HD cameras go it's tough to choose between just these two because of their similarities, but the differences (particularly the negative ones) can really make the decision easier.
The JVC records to SD cards which is so much easier to use in terms of capturing/editing than tapes. I've also had more experience with the JVC in the TCF department so it's easier for me to feel comfortable with it. The disadvantage I see is it's size. It is so small I'm afraid of breaking it and (even though I know I'm wrong) I feel like my fingers are too big for the buttons/dials at times.
The Sony I feel has better control over all the technical aspects than the JVC, I feel more okay handling a bigger camera like this (perhaps a throw back to my days of making movies with my Dad's VHS camcorder as a kid). Like I said above the tapes are the disadvantage for this camera, they are a pain after you've gotten to use the JVC.
Having expressed all this, I chose the Sony HDV camera for my portrait of a place. I don't want to only work with the things I am familiar with, I want to venture out of my comfort zone and try everything out to see how they all work.