I've looked at many pvr's, as I just built one, and nothing was close to mythtv in terms of features. However, nothing was close to it in terms of difficulty of installation either. Took me over a week to get the whole system set up. However, it's multiple computers all networked together, a backend and two frontends. One backend records programs centrally, then all the frontends (one per tv) can access programs from that database. It lets me rip dvd's to the hard drive and transcode them to save space if I want. It has a weather module, a video module, a music module (cd's and mp3's), and a gaming module. The gaming module emulates nintendo, super nintendo, atari, and arcade games (through mame). There is a photo viewer / slide show module. I can play dvd's directly from the computer. It has a browser and an rss news reader.
It really does just about everything one could want. I think the best feature overall though is the flexible multiple computer frontend/backend setup. The videos, music, and games are stored on a separate file server. I can access all of it from any of the 10 computers in my house, and many of them are also set up to act as front ends, so I can watch live tv or recordings while I game or surf the web.
It's a very nice system, but it's a royal pain to set up, so many things to get working.
