Most private trackers have some sort of bonus point system now where you earn points per hour of seeding per torrent, regardless of how much data you actually upload. You can then use those points to buy upload credit and raise your ratio

There are some niche private trackers which have an active community that handle quality and requests. Also they don't let just anyone create a torrent, so you can have assurances that the files have been vetted to some extent and you're not going to download something unexpected.

The advantage of private trackers is that:

• torrents almost always have seeds
• you can ask for re-seeds in case they aren't
• torrents have a good quality
• you're less likely to receive a complaint letter from copyright holders