It depends.
You need a Series 1 or 2 standalone. DirecTV TiVos only record form satellite.
Later Sony S1s, and all series 2s except DVD units from Toshiba and Pioneer need subbed to record at all. Earlier Sony, all Philips Seties in, and Toshiba and Pioneer units can record without sub.
All will buffer Life TV without a sub.
You need a Series 1 or 2 standalone. DirecTV TiVos only record form satellite.
Later Sony S1s, and all series 2s except DVD units from Toshiba and Pioneer need subbed to record at all. Earlier Sony, all Philips Seties in, and Toshiba and Pioneer units can record without sub.
All will buffer Life TV without a sub.