I also have been testing the HDTV Mate with the GTMEDIA G2 Plus Android Box. I tested it out for about 5-6 hours today. I REALLY want to LOVE the HDTV Mate but there are some issue that need to be worked out, no doubt about it. This is the first time i have had something that will do ATSC3.0, so this has been super fun for me, and i think this device with a few tweaks could be great, especially for the price. The built in signal meter is totally worth the price just for aiming Over The Air antennas in my opinion. Here are my test notes:
After installing the HDTV Player app, i scanned in my channels, and it scanned in almost everything, but it missed the Channels at 605 MHz (digital 36), 49.1 here in mid-michigan. I scanned these in manually but the signal is so low they will not play. With the antenna connected directly to the tv, these play just fine, never have an issue.
All of the ATSC 3.0 Channels scanned in and play fine with the exception of CBS 5.1 (DRM encrypted). FOX, NBC, ABC all played great. Excellent picture - video and audio worked great for me, no issues. The big surprise was that the ATSC1.0 versions of these same channels had stuttering and interlacing problems. Definitely noticeable.
On Channel 5.1 (CBS) there are several sub-channels. The ATSC1.0 version of 5.1 worked, but 5.2 and 5.3 even though it shows a great signal the channels showed a blank screen, 5.4 and 5.5 worked just fine. I connected the antenna directly to the TV and the all came in fine like usual, so i have no idea why they (5.1, 5.2) would not play with the G2 and HDTV Mate.
The epg loaded pretty well for all of the channels i scanned in with the exception of one channel. This channel has 6 sub channels and the 6th would not show an epg at all. Even after leaving it on that channel for 30 minutes. That same channel the epg comes up just fine on other tvs.
I did not test any PVR, this is not that important to me. Certainly not as important as all channels scanning in, playing correctly and with good epg.
Now as far as these 3 issues i mentioned with the GTMEDIA G2 Plus Android Box and HDTV Mate combined, I also checked these same things using the HDTV Mate connected to my Android phone and saw the same issues except i can not say i noticed video interlacing or stutter really on my Android phone. Probably because the picture is so much smaller, or maybe faster processor than the G2 Plus? I dont know. On the Android phone when i tune to an ATSC 3.0 channel i am able to see the "This is an interactive channel logo press right". I do not see this when using the GTMedia G2 Plus Box.
I really do not care about the interactive aspect of the ATSC 3.0 channels. I am only interested in the fact the signal is stronger for me on these. 16 miles to the tower with all the ATSC 3.0 channels, verse various distances for the ATSC1.0 versions of the same channels from 24 to 40 something miles.