I think xolox is one of the better file sharing programs out there. I like the fact that it is very simple and easy to use. However, two things would make it even better. First would be a bitrate for the mp3s. I can use another program like Morpheus and search for the same files and compare the sizes to determine the bitrates, but having the bitrates in there would make it much simpler and less time consuming.
Another would be the resolution of videos. I don't normally download any videos that have a resolution below 320x240. Since there is no preview option, you can't really test it out. Either a column for resolution or a preview/player added would be a great asset. If these could be incorporated in the next version that comes out, I would probably use Xolox exclusively. Until then, I'll use Morpheus and Audiogalaxy along with it.