The DTC-ZA5ES is a 4DD / 2-heads design and Sony's last full-fledged consumer DAT recorder, introduced at the ES line's true turning point.
It is a good recorder, it is also reliable, has 4-DD drive, PULSE analogue-to-digital converters, Advanced-PULSE + SCORE 1-bit digital filter, has SBM, can record analogue sources at 44.1Khz...
Kept from the DTC-2000ES were the MIC / MIC att switches, the fader function, the clock modes to keep on the tapes the time/day of the recordings and, practical, the rehersal modes for nudging markers.
It just was a bit of a let down when one had seen (and used) a DTC-2000ES : the incredible build quality and finish lavishness of the previous DTC-1000ES, DTC-1500ES and of the DTC-2000ES was not there.
If the front and top enclosure are of beautifully finished aluminium, the rest is only pressed metal sans copper-plating, two boards with everything on them and a tiny transformer.
Comparing the internal componentry and structure just proved what happened between 1993 and 1994 at Sony : the DTC-ZA5ES is almost an empty box.
It would get worse later on, though : worse is always possible :)