Cell Reception Issues
You didn't mention weather or not the two phones you tested in Vermont were on the same carrier or not.
I have noticed that Korean Androids (Samsung and HTC) seem to get consistently good reception in direct comparison (same location same carier) to Chinese phones (Huawei and ZTE). Google could put more quality control restrictions on the manufacturers reception (but probably will not)
Then there is the added complication that the cells themselves (towers not phone) are in a constant state of change.
I recently had an experience that demonstrates this. I live in a community that has a T-Mobile Tower 3 miles away. The terrain is absolutely flat, no hills no tall buildings, I can actually see the T-Mobile Tower from my house with a pair of binoculars. For the past 10 years T-Mobile has had great reception here. 1G, 2G, 3G...I recently discovered that this tower had been upgraded to 4G just about the time that the T-Mobile service here went from excellent to non existent. We ended up having T-Mobile buy out our contracts becasue we simply could not get service.
I'm wondering if the companies that own the towers and rent them out to the carriers are just doing a poor job of maintaining equipment capable of running all the different tecnologies, 2G, 3G, 4G, LTE etc..