Well, be careful. I have a TiVo S3 and a Comcast Motorola DCT-3416, and I have more video problems on the S3 than on the 3416. (I do have more audio problems on the 3416, and have resorted to RCA connections for audio from the 3416, rather than TOSLINK, to avoid those audio problems.)
Each of the two options have their own strengths. They're roughly the same in cost (TiVo is slightly higher), and roughly the same in overall value (again, TiVo is slightly higher).