Well I think I was actually the first to report this in the big 722k thread. My OTA reception issues are similar to Scott and Claude's. In a nutshell it sucks on the 722k but is fine on my 722 and 622...
I don't know enough about the technical or internal aspects of an ATSC tuner or the software, but I can confirm that they did something that returns higher signal strength with L651.My OTA signal strength readings seem to be higher with L651. Anyone getting any OTA channels they couldn't previously get before L651? Maybe they addressed this issue in L651.