A Series 2 has only an analog tuner to record from, so what would you do when those analog signals are gone? OTA has already gone digital, most cable companies have gone digital with only a few analog remaining.
I suggest not getting a Series 2, but a Series 3/HD or a 2 tuner Premiere, since they have both analog and digital tuners. The newer Roamios only has digital tuners.
BTW, you have not noted what is your source for TV, OTA, cable, satellite?
The Series 3/HD or 2 tuner Premiere will only work with OTA or analog/digital cable or both at the same time.
Series 2 (80 hrs,PLS, Retired)
TiVo HD 1TB (157 HD Hrs, PLS, "S3HD")
Roamio, Oh Roamio!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!