I have 4 methods of getting HD locals via OTA. H20, HR10-250, HR20 and FusionHD card on Vista Media Center. I then also get network locals via the H20 and HR20. I cant really see a difference. There have been some issues with 8 mm issues on 1080i ones in the beginning but that issue is fixed and ancient history.
So on an eyeball basis, I cant really say the OTA is substantially better then the MPEG4 versions over sat via 4 different types of HDTVs (2 LCD's, CRT, Projection). I tend to use the OTA channels since I cant imagine they wouldnt be the best but its clear to me D* chose the right technology, has worked the bugs out, and should have a good future using MPEG4 going forward.