Why do the Standalone TiVo DVRs have four levels of recording quality, but the DIRECTV/TiVo units have only one?
DIRECTV’s television signals are compressed digital signals. The DIRECTV/TiVo units are equipped with technology that allows the TiVo to record those compressed digital signals directly to the TiVo’s hard drive. Therefore, when the signal is recorded and then played back through the TiVo, there is no quality loss. Thus, the DIRECTV/TiVo units record in only one quality: Best.