I have beyond TV and it is indeed an excellent piece of software, especially since it is almost half the price of MCE. The only thing it doesn't to that MCE does is play media files, however if you buy BTV you can register for snapstream's beta program and download the beyond media beta, which is basically snapstream's response to MCE.
So for $65 you get the best tivo-esque program going and if you are willing to be a beta tester you can get the Beyond media program as well.
Beyond TV (and I assume Beyond media as well) also works out of the box with the ATI remote.