Appearance - the Sony brand has buttons and a small joystick on the front. It also has a more high-tech appearance. The Sony is silver; the TiVo-branded and Humax-branded units are black. The TiVo TCD540 and TCD649 series also have a nightlight on the front of the unit that can be controlled through the TiVo interface. The TCD540 unit is gray with a white light; the TCD649 is black with a white light.

Remote - the Sony, on one hand, and the TiVo and Humax, on the other hand, have different remote designs (and different remote codes). The TiVo remote has a switch that enables you to switch between two TiVos; the Sony does not. The Sony and Humax remotes are silver; the TiVo remote is dark gray (TCD540) or black (TCD649).

Hardware - The Sony has an internal drive bracket that will hold a second drive. The Sony also has a large power supply that is sufficient to power up two drives. The TiVo-branded unit and Humax-branded units all require the TwinBreeze and the PowerTrip to run two drives.

Features/Functionality - The TiVo/Humax Series2 standalone units and the Sony SVR3000 all have the same basic features and functions. The both also support the home media feature. The TCD649 TiVo model has a second tuner that will enable you to record two shows at the same time under certain circumstances. Specifically, you can record one channel from any source other than antenna, and another show from an analog, non-scrambled cable channel through the RF input