Updated report on reception:
The location is right on Gun Lake, so it's near several broadcast towers. But, they are all in vastly different directions, so I didn't know how various antennas would behave. The antennas we tried were: cheap rabbit ears, Terk TV55, Radio Shack Omnidirectional (flat disc antenna), and Radio Shack 15-2185 (has wings, like the ChannelMaster Stealthtenna).
The local channels, WOOD/WXMI/WWMT/WOTV, were easy to receive. Even the rabbit ears could get them at ~60% on the signal meter. The RS disc antenna was about the same as the rabbit ears. The 15-2185 got a stronger signal, but required pointing of the antenna to get the strongest signal for each station. The Terk TV55 got 3 of the 4 at 100%, and Fox at ~75%. We ended up keeping the Terk and returning the others. We mounted it on the of the chimney, about 25 feet in the air.
I got absolutely no signal reception on WZZM and WZPX with any of the antennas. But, we already got WOTV, so WZZM was not a big deal.
On WGVU, I didn't get any signal when I tried most of the time. But, after mounting the antenna on the chimney, I was getting 36-63% with no dropouts all night on Sunday. Monday morning it's not registering any signal again. I'm not sure if it's because of the weather, or if they don't broadcast during the day.
We watched the HD football game on CBS yesterday. The still shots looked good, but the motion scenes were terrible.. very blocky as if bandwidth constrained. The HD games on ABC and ESPN-HD looked very good.