The Organ and Keyboard Cavalcade magazine available in the UK has tested and reviewed the Ketron SD1 and they thought very highly of it. It was a great review. Also, for studio use, it is definitely good.
Being one of the first few people to actually own one of these in the UK, I've had it quite a long time now and can recommend it to anyone who is wanting a top of the range arranger keyboard that has great sounds, styles, ease of use, vocaliser etc. Also, Ketron are great at listening to user comments/improvements and implement them into their new operating system updates.
I also have a Roland G1000 which is a good all rounder and a new Genesys. None is better than the other as they all offer something different and don't sound alike.
The Triton range is excellent and the new Gem pro mega piano is superb, it all depends on what you need.
The Gem Genesys is like having a studio, as you can burn your songs direct to it's internal CDRW. It saves me time having to muck about with sequencing software on PC when I want to record something quickly.

[This message has been edited by eyrec (edited 09-23-2002).]