[felson]

i agree with n82 and astro. i have a series 2 with the lifetime subscription, which i purchased myself, not from ebay. i also have a high-def dvr for my newer tv, rented from Time Warner Cable and manufactured by Scientific Atlanta. (i bought a 55" sony rp-lcd last year -- thanks for the advice astro!)

the tivo interface is ridiculously better than the other box. plus the SA box reboots a couple of times a week, a problem which I've heard is common to these boxes. the series 2 is much stabler, and i suspect the series 3 is pretty stable too. if it weren't for price (series3 is ~$800), i would have bought a series 3 already. (btw, even with a series 3, i think we need to rent a separate cable box to support video on demand -- can someone verify this?)

regarding lifetime of the unit, my series 2 is ~5 years old. i did have to replace the hard drive once, and my remote just broke, but other than that i have had no problems.

if you only need standard def, buy a series 2, and probably with the lifetime subscription. if you need high def, then it just comes down to price.