The SD1 has the sounds you'd need for rock; the built in FX unit includes "combi" effects (and the leslie simulation is excellent) so there's are some good distorted / echo / leslie B3's in there. The synth architecture and controller routine is extremely flexible and powerful. Like I said, were it not for the TLC and reliability issue I think it would do you a very good job.

I agree the SD1 is rather old but - apart from the tuning - it still sounds fabulous and to me was not surpassed by any newer Enqoniq.

Their later models (KR 76 was thelart) are still pretty good. Ensoniq are now for all intents gone - taken over by EMU. I think the last Enqoniq model was the "Fizmo".

Also I remember looking at the Gem "Equinox" models; the internal architecture looked reminiscent of the SD1 and the sounds were very good.