I purchased 2 MT-2 tuners, originally I had 1 of em in my 722k but later moved it to a 222. This was around the time that ppl were having problems w/ 722's not functioning properly with the module inserted. My other module is in my 922. The 922 of course has sling built in and I am abe to view OTA via sling without issue. Allthough, right now the module isnt detecting any channels (I just recently replaced the 922 and "may" have hooked up the module wrong, I havent really had time to investigate that further). I do see 1 distinct difference, or at least did on my previous 922: I pretty much had guide info for almost all the sub-channels; in contrast, the 222, most of the sub-channels just say 'digital service'. Not sure why 1 recvr would have the guide info an not the other.
I use it much like everyone else, to watch tv during storms and when snow builds up on the dish. I also get channels from Baltimore, like Fox/ABC, etc, that I can't get obviously from dish (since they can't sell neighboring markets/significantly viewed channels). I would say I use the dish channels more than OTA, but its always good to have. Comes in handy during the NCAA b-ball tourny: I can record the TNT & TBS games off the bird, an CBS OTA, all a the same time. And yes, recordings of OTA content are twice as large as off-the-bird. But sometimes its handy to record OTA so as to not use up any existing SAT tuner.