If you have an unmodified Series 1 TiVo, the benefits are:
- Dual Tuner: this WILL work with your Digital Cable box. It will use it just like your Series 1 TiVo does, but will in addition have a built-in analog only tuner that will allow record analog programming at the same time as recording analog or digital from the cable box.
- Home Media features: access to photos, videos and music stored on your PC, as well as the ability to store TiVo-recorded videos on your PC
- Access to Amazon Unbox videos as well as TiVo Cast stuff
- Set up recordings remotely through the web
- Possibly Multi Room viewing with Series 3 TiVos in the future (though this is not 100% sure)
The negatives are:
- the DT will be "single tuner" just like your series 1 is, when cable companies drop analog and go all digital, since it will need a cable box to receive signals. Noone knows for sure when this will happen.
- unlike your Series 1 TiVo, the DT series 2 can not receive "over the air" broadcasts from your local network affiliates. It only works with analog cable (full dual tuner capability), digital cable (limited dual input capability as mentioned above) and with satellite (only single input - no dual tuner functionality).
If I were you, I'd update. I use the network functionality of the Series 2 every day. Probably more than I use the actual recording-functionality of it (especially the PC-to-TiVo video stuff).
But if that's something you know you won't be interested in, it might not be worth the upgrade for you.
EDIT: oh, and when did you activate your Series 1 Lifetime? If it was before January 20th, 2000, there is no need for you to take this offer - you are allowed a free grandfathered Lifetime transfer to any other TiVo model, including the Series 3 high-definition recorder.