We just pushed out 2.0a.26. We have been working hard over the last 4 weeks to try to be a better firefox extension and we have some good results to share with you: we have able to maintain the initial page load time for the digest and the cover while reducing the network traffic by 75% and the memory footprint by 25%. We also fixed a couple of edge cases regarding gmail integration/google apps integration (login, address book and groups support) and unread counts getting out of sync (being too aggressively cached).
Here is the link to upgrade to feedly 2.0a.26. Please let us know if you run into any regressions.