As a former Tivo Evangelist, I can tell you that I prefer BeyondTV to Tivo. But if you're married, check the Wife Approval Factor first.
We've had our BTV set up for over a year, and after awhile, I had to ALSO set up the HD Tivo for her. She started off excited about the new system, but quickly missed the Tivo remote, the Tivo guide and the Tivo "feel".
Over the year, she's slowly started using the BTV box as I've added her favorite movies and TV shows in Divx onto the hard drive, added the Tivo sounds, networked her computer as a BTV Link machine and got a Harmony remote, but it's been slow going.
Unfortunately, the BTV guide is truly painful to use for anyone who's ever used the amazing Tivo guide, as I posted here earlier:
The Tivo Guide is the ONLY thing I Miss in BTV
Jeff