My limited experience with beta7 has been problem-free but I note the following changes that might interst others with offline conversions.
I installed the beta7 (with new FFmpeg) and saw that the 0-100 quality scale was unchanged although actual qualities available now vary greatly. Previously, I just left the quality setting at 100 for all my conversions. By experiment I think I have found that for HD TV recordings I need to set the beta7 scale to 30 or so to get a bit rate equivalent to the beta6 100 setting. For SD, however, I seem to need a higher setting, 40 to 60, to get the conversion quality I got with beta6 at 100. Also, it appears the beta7 adjusts the audio bit rate. I don't know if previous versions adjusted the audio rate depending on the quality setting because I always transcoded at 100 but my beta7 audio bit rates vary from 64Kbps to 160Kbps.
I tested a five minute HD clip and found a 30 gave me a 1280x720 1200Kbps recording while a 100 setting gave me a 6100Kbps recording with, of course, a five-times bigger file 40% the size of the original 1920x1080 MPEG2 clip. For me, 100 is overkill but I expect it will at least partly satisfy the quality-fans.
(First post so let me add thanks for the software. Air Video and Atomic Web Browser account for, oh, 90% of my iPad usage.)