I was wondering whether there is a consensus regarding the picture quality for the LA or NY locals from people who previously had viewed the MPEG-2 transmissions and are now viewing the MPEG-4 version.
It depends highly on the local station, some are better than others for mpeg 4 pq. However, even with the better ones, the pq is a bit better than mpeg 2 at this point, but you are prone to more technical issues particular with the audio, hopefully they will fix this soon.
Ideally if they are passing the MPEG4 stations at full resolution, they should look better then the HDLite stations being broadcast over MPEG2. I don't know if anyone has been able to confirm the resolution of the MPEG4 locals yet.