Your observations align well with mine. I am close in (12 Miles to the antenna farm) and don't have much trouble with reception, although it seems to be more difficult to receive the VHF channels using the built-in monopole antennas on portable sets in some rooms of the house. These antennas are really too short to be very effective at high band VHF frequencies. In stormy weather, I see more "breakup" on the UHF channels, likely due to wet blowing trees.
My one "DX" channel is about 70 miles distant on ch 7... Analog era, it was decent with a moderate sized outdoor Hi band Yagi... during the transition period the digital was on UHF channel 37(?) and was great with a moderate sized Radio Shack corner reflector/Yagi. After the transition/analog shutdown the station returned to ch 7 (digital) and I can only receive it on rare occasions (mostly early mornings and late evenings) using the Hi band Yagi. The contour maps shown on the FCC site are virtually identical for all three permutations of the channel.
Found this article, with much hindsight, discussing some of the problems related to the standards that were set 20 some years ago:
http://www.tvtechnology.com/article/...d-power/203114
jr