So far, this looks like the best firmware to date, and with the least reported problems. the next 24 hours or so will tell....if this will be the next national release coming out maybe some time next week.
Early indications are that this version (11b) is stable, fixes the majority of reported issues, and is faster in terms of the guide and menus.
My brief 2 hours of testing with it has not uncovered a single flaw. MPEG4 and MPEG2 recordings, old recording playbacks, Dolby audio, OTA channels, trickplays, are all solid. It's encouraging that with this release, the HR20 (now about 120 days old) is finally getting to be the HD DVR everyone hoped for to the mass DVR audience.