Transfers are limited by the CPU transcoding the videos, that's why its slower. Premiere is faster, faster CPU.
Video of transfer speeds.
Series 2 (Retired, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "S3HD")
Roamio, Oh Roamio!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!