I have the HD100, and the DR100 to go with it. it seems to me that the majority of people complaining about the hard drive are matching it with some other camera. the DR HD100 was built for the JVC cameras. the FS versions are for everything else. some people get that confused.
I havent had a single problem. I love having it, it makes deadlines feel a little less problematic. when you shoot an hour of video and it only takes you 10 minutes to get it into the NLE, thats 50 extra minutes of editing time....whats not to like? i know some people hate the multi clip thing. I usually prefer to have it all as one clip, and sort it out from there, but I have gotten used to it, and it is actually easier to find your SOTs and various b-roll shots when they are allready broken down, ya know?
and between its battery, and pulling power from the camera battery, I can shoot for a full day before it gets low on power, which is nice as well.