One thing I forgot to note...Mike is/was a satellite dealer years ago and use to do installs of large commercial satellite dishes in Alaska and also did some work on the Mt Wilson (LA) Antenna farm years ago. So he knows his stuff. Here is a couple articles
Anywho the thing with VHF Low is most of the stations that use it are smaller markets that could save money by not moving to a different station. Also in those areas most folks already had outdoor antennas so it wasnt that much of an issue. As example a few of these network (Big 4) stations right now on VHF Low
-Bangor Maine (which right now is very unique as you only need a VHF antenna to get all the stations. All 4 commercial and PBS are on VHF. A couple have UHF translators but they are on 2 (NBC), 13 (CBS), 7 (ABC/FOX) and 9 (PBS)
-North Platte, Nebraska (they actually have 2..NBC on 2 and ABC on 6)
-Calumet, MI (UP of Michigan)
-Butte, Montana (2 of them..CBS on 5 and NBC on 6)
-Glendive, MT (KXGN flash cut on 6/17/09...they never had a "companion" channel
-Lead, SD (satellite of Rapid City station)
-Bristol, VA (Tri Cities)
-Quad CIties and Des Moines, IA also have VHF Low stations but have UHF translators also
So as you can see outside of Philly I would say Albany being the next biggest market that has a VHF Low network affiliate. What is nuts is there are some stations who decided to cash in their chips and move from UHF or VHF High to VHF Low in exchange for a payout including the PBS stations in Pittsburgh (WQED), Boston (WGBH) Los Angeles and Rhode Island. So that outta be interesting when folks with antennas there lose those stations.
VHf High isnt so bad as long as you have the right antenna.