There is no doubt in my mind that the Glomex unit is superior. But it is ten times the cost of the cheap unit that brings in all the stations in Central Florida. Apparently it lacks an FM-blocking filter, since it seems to get all the FM stations too. I prefer watching movies on disk, but the TV is good for weather and news.
The Rosewill unit uses an in-line power injector that runs on a 9 volt wall wart. I am OK with the ac requirement because the TV needs ac anyway. When I get the TV on 12V then I will power the injector from 12v too.
Incidentally, many of the new LED HDTVs in the 20" to 30" range run on 12V, and can be powered directly from the boat. The problem is, they want 12V, not 14.6V with alternator spikes and system noise. I have built a box for my computer that regulates the battery voltage to an even 12V for these sensitive loads. If anyone is interested, I will do a howto on it.
1975 32' Flybridge Sedan, twin Perkins 6-354 diesels, 1:1.53 velvetdrives, 16 X 19 props. Merritt Island, Florida