It's not really an alternative to torrentz though, is it? As far I can see, it only has kat torrents. It does not list other public trackers..

Yes, that's right. It's worked for me as a reasonable replacement for kat for now. Also, the site isn't anywhere near as good as kat but I'm sure given a little more time they'll improve. Or someone else will come up with something even better - I'm sure these folks will have learned alot about what to do or not do when running such sites.