Features: ATRAC 3.5. Portable recorder with docking station. Li-ion (LIP-12) rechargeable. Resembles slightly thicker MZ-E3. LCD on both body and headphone remote. Has no titling or editing buttons (on docking station instead). Away from station, portable unit has only playback and mic-record functions (with AGC or manual level control). Docking station: large LCD screen for titling and displaying other information. Provides line and optical i/o connectors. Sampling rate converter. Date and time stamp recording with station or portable, display on station only (AM/PM format). Playback: LiIon: 6.5 hr, NiMH: 3 hr, AA: 4 hr, LiIon+AA: 10.5 hr, NiMH+AA: 9.5. Recording: LiIon: 4 hr, NiMH: 2 hr, AA: 2 hr, LiIon+AA: 6 hr, NiMH+AA: 6 hr. LiIon recharge time: 5 hr, Power consumption: Rec: 1.0W, Playback: 0.7W

Mis-Features: Only records left channel when mono-recording from a digital source. Cannot turn off auto track marking when recording from an analog source. Portable unit does not have A/C adapter power socket. No wireless remote control, even when docked. Divide point is as accurate as your ability to push the pause button (no 60ms positioning with rehearse mode like the decks).

Links: Sony Japan Page Pre-release info (and picture). An initial report on the MZ-R4ST's look and feel.

Reviews:

User Manual: J/E