IRC there was nothing special about them except the FF and SCSI onboard.
Of course it's a rarity and has value because of that, but technicallywise it's the same as an A4000.
Actually they didn't even have the FF...the only
cool things about them were the SCSI and the
programmable DSP, but even if the DSP worked
there's no software (or documentation?) for it.
Cool for collectors, but "IMO" an original
Commodore 4000T would be a better find.