Yeah this is my setup. Sure it does mean you have to pay for a couple of things, but I find its the best way. Plug a Usenet provider and a couple of indexers into the aars, set it as highest priority, then some decent torrent trackers as lower prio.
Usenet will handle grabbing the majority of your requests without having to worry about seeding, ratio and such and the torrent trackers act as a fallback and for stuff like season packs which don't tend to get uploaded to Usenet and anything older or rarer that might not be available on usenet. So far though I've found it's not too much that doesn't get grabbed by usenet, but the torrent trackers are a nice backup.