Anyone know of a rear rack that will work with panniers that can be described as quick-release? Specifically I'm looking for a rack that doesn't just attach to the seatpost, but also has the "legs" that attach to the rack holes in the frame near where the rear wheel attaches.

I always thought it would be nice to have those legs be hollow and just slip over a small posts that that you attach to each side of the frame near the wheel. Combine that with a quick-release clamp for the seatpost and you've got a sturdy rear rack that can be quickly put on or taken off. Haven't found anything like this, though.

I've never heard of one like that before. Since I had one stolen I can see why you would want to remove it. I cant believe people would go through the trouble of stealing one os these. The thieves made my commute a pain that day as I had to carry all my stuff and ride the bike. At least they left the bike...that time.

https://www.topeak.com/products/rack_beam_lead.html

Topeak makes racks with a quick release seat post clamp, and have side frame extenders that accomodate panniers. I don't know how stable the set up is, but it sounds close to your need.