I have an SD-5, and I've been playing an MS-60 (two, actually-the SD-5 is almost a direct upgrade-same speakers, amplifier, etc.) for over 14 years. They're still working perfectly, so I'm still getting used to the SD-5 in the office.
Ketron is the BOMB! Sounds great, and I'm in familiar territory. Still use the old Ketron (Solton) stuff at least three nights per week on a house job.
Operating system is a little different, but it is my brand of preference by far. There are some resale issues (depreciation) and I personally have some problems with the practice by an in the distribution organization selling equipment directly and bypassing distribution (an absolute NO-NO in my book), but the equipment sounds great and is built like a tank.
R.
[This message has been edited by captain Russ (edited 05-20-2008).]