They did used to be really good, back when Red was at Uni and running the show. Of course back then it was only for Creative players but you used to get email responses in hours and bug fixes in days.
Alas as with many student projects as it expanded and the people who started it got other interests/jobs the personal touch disappeared, I'm not even sure if Red is involved anymore.
I've used there software for my Zen, Karma and iPods and it was such a blessing having an easy to use, powerful, single interface for all my mp3 players.
However I don't think they've actually released any real updates for any of there products in many many months now which suggests to me that the developers aren't involved anymore and it's just someone running the website to make cash.