Reeder crashes for me if I leave it open all of the time, usually sometime between the 24-48 hour mark. But if I'm just opening it, reading, and then closing, it seems to be fine.

Ditto, though I open it maybe 3-5 times in a day and rarely have more than 50 or so articles queued up. Also, I open links in Safari instead of the built in web view on both Mac and iOS.