I think you were referring to me; well, I have had my SD1 for 5 months now and I had to take to a Ketron repair center twice; the first time they changed the filter board and the second time they changed the mother board plus another minor board. When I complained with the repair man about these issues, he replied: "Why are you complaining? You've got a brand new keyboard and I have replaced more than 300 dollars worth of parts for free!". True, I even have OS 3.0c installed directly on the motherboard now (no need to load it from floppy disk anymore), but my keyboard was supposed to be new even before and frankly, if I were a gigging musician making my living out of music, after these experiences I would always take a spare keyboard with me in my gigs!
All that said, during the time I hadn't my SD1 I really missed it and realized how precious it was not only to record tracks, but just simply to make music. I have been listening to all the Tyros MP3s available and, while I agree that the sounds are really good (some of them better than the SD1's), I think that Ketron still rules, style-wise.
I am so in love with the Ketron styles that I have an XD3 in order: this way, if the SD1 leaves me alone one more time, I will sell it and keep the XD3, together with my VA7 and maybe a Tyros...