I threw Ubuntu on it and then setup rtorrent, rutorrent, and Apache HTTP Server.
I only use private trackers like what.cd.
I'm still trying to determine the best way to transfer the data from the server to my media box. At this point I use lftp with sftp which is working out well, but I want to set up an automated system.
Also, I hope you don't mind me asking (not fishing for an invite) but: How did you secure an invite to what.cd? Did you by any chance do the interview?
It depends on the private tracker. The key is to reciprocate - I initially did poorly on what.cd and had my downloading privileges revoked. I got on Bandcamp and found free albums and just started uploading FLAC content. Now I'm a power user with a nice buffer.
I had better initial experiences on other private trackers but I prefer what.cd's ratio system.
Upload Rates:
what.cd is pretty good about this. I have yet to find something I wanted that didn't have someone seeding. Other private trackers I frequent aren't as good about this.
Prevalence of Malware:
I run Linux systems and primarily download music from private trackers. I get other media over Usenet. So I haven't really had any issues with malware.
Media Coverage:
I'm not exactly sure what you mean.
Invite to what.cd:
I did the interview.