If you are doing music videos, I would recommend the DVX. It acheives that much needed film look, since most high-end videos are actually shot on film. For the inside stuff, make sure you have enough light, and watch the contrast. With cinegamma mode, the whites clip hard if overexposed. So lighting is very important. It may look to bright on set, to the naked eye, but with a properly setup monitor, you should be ok. Also, you have to watch how you move that camera. 24p judder, although filmlike, can become distracting with fast pans.

I own both cameras. Technically, the sony dsr300 is a much better picture. But, for aesthetic purposes, I am inclined to use the DVX100 with 24p. The "filmlook" is very nice, and gives a better "feel" of the images. Then with minor tweaking in post, the picture is very, very nice. It depends on what you are shooting as to what camera to use.