I got an apple tv used this weekend, A1427 model with 6.1 and no issues so far. So hoping it is just a random bug here and there. I did try to mess with wwe network, it didn't work, and then after that movies from home sharing wasn't working. I restarted the apple tv, all good as the apple tv is just for home sharing and apple stuff, I got apps like wwe network and such on consoles.
Oh yeah, i redeemed a few favorite movies with itunes (can't stand that ultraviolet crap) and I added another movie to my collection. I found a weird bug: Newest movie, I hit play the first time it spins and the bar shows it is playing, nothing happens. I back out, open another movie play it for a second or two, then go back to the new movie, poof it plays and from there on out all is good. I don't know if there is something the apple tv is doing vs reading my home sharing, but overall 6.1 has just minor bugs, but it is affecting others. I hope 6.1.x comes and squashes the bugs as when I get on a stable version, I will stick with it as home sharing is my main use for the apple tv.