chas - The only stereo linkup I have used with the XK-1 are my CM-30's with a sub, but that was a small room. The separation and Leslie simulation was very good in that situation. With the 808s I run Mackie i300's for the mains and have used a pair of Soundtech 12" wedges for monitors. So I run mono, mains and monitor mixes. There might be a slight stereo feel by hearing both mixes, which I can usually do.
My thought would be if stereo speakers are separated too far apart, you might get more of a rolling phase than a doppler effect, but that's just speculation on my part. Run thru a mono setup, I feel the XK-1 Leslie is pretty darn good. Sorry I couldn't be more helpful.
Still loving my E-60, XK-1 setup, but I could live with the G70 again if presented with the possibility. I'm not looking or asking, just stating. The G70 has the best stage keybed I've ever used.
Harold, sorry for hijacking your post. Back to you, bud.