Steve, I didn't notice anything on your link that mentions dimensions, but, that "stand alone" camera looks pretty big compared to the ones that plug into a camcorder.
I would guess the record quality is never going to be as good as a good camcorder, but depending on how good your camcorder is, the stand alone might be better.
You shouldn't worry about knocking it around in the tree. Camera bags like Lowe Pro etc are pretty good and clip nicely onto a tree magic. If, and I assume you are, you get a treemotion, you'll definatly be able to secure it well to that. Has your camera got time lapse function? I don't want to see any videos of you working at normal speed!
I just reckon that a mini plug in camera would be more versatile for other things, although I guess the stand alone is hassle free. I'm sure you'll decide and I'd be interested in the results. Camcorder is on my list of techy things to get at some point!