Lesse.
My 1st DVR was a Happauge(sp?) WIN DVR on my old Windows 98 comp, back in '99. I used it mostly to make VCD's of shows i'd record.
When TIVO came out, i bought one of those with DirecTV. Ditched it when Microsoft released the Ultimate TV PVR. Mainly because it offered the dual TV signal (record 2 shows at once) that TIVO didn't have at the time.
We just recently switched back to a TIVO/DirecTV box on account of the old Ultimate TV acting buggy and also because DirecTV with TIVO had an unreal deal that guaranteed that along with the lower monthly fee for the service, the box would literally pay for itself. That plus TIVO finally got the record 2 shows at once feature...
The comp i'm on right now has an intervideo WIN DVR too. I mainly use that for when i'm transferring stuff from the PVR consoles onto my comp for DVD burning.
As far as convenience, i'd say the Ultimate TV's features, menu's and ease of use was better than TIVO by a long shot. Ultimate TV was a hell of a lot more user friendly and easier to program only the shows you wanted to see.