I can’t say I had the same negative experience with 4.1 as other people. My xVid movies played just fine, streaming over WiFi / SMB from a windoze box. I did notice that the startup movie had no sound, but that’s a minor nuisance.
Updated to 4.1.1 yesterday, everything seems OKish. Still no startup movie. I have to say, I paid 90 bucks or whatever a few years ago for aTV Flash and I’ve been very satisfied. New features, regular updates, relative stability, and very easy to use. Thanks FireCore!