Series 2s offer one advantage. To be used with digital cable they need something (which you have to rent from the cable company) that tunes the cable channel and sends it in analog form to the TiVo as either NTSC Channel 3/4 or composite video/stereo audio. This lets you record "not originally an OTA" cable channels and still be able to copy them to PC via Desktop or the open source stuff. If you've got an S3 or higher, you have to have a cable card for digital cable and are at the mercy of the cable company's decision to set the CCI bit. (why yes, I am on TWC, how could you tell?) Although apparently if the cable company really want to be pr**ks about it, they can slap some Macrovision on the analog output of cable boxes and DTAs, and the S2 software will honor that.