I owned an XK for a while and had a lot of respect for it. It was a camera ahead of its time, but it came at a price:battery dependence. When it was released, the pro standard was the mechanical Nikon F2 and Canon F-1, and pros were very leery of battery dependence. Eventually they got over it, but it was far too late for the XK. Another problem with the XK, a fatal flaw I've always felt, is if you wanted one with a motor drive, you had to buy the XK Motor with its built-in motor drive. The XK Motor is beautiful -- it's a work of art. But Minolta should have been thinking more in terms of modularity with respect to motorized film advance. I mean, they had interchangeable finders and focusing screens, why not interchangeable motor drives as well?
When it comes to a very smooth film advance, I like the advance on my XD-11 very much, but I think my lowly Contax 139 Quartz has a smoother one. In fact, of all the cameras I've had the opportunity to use or to try out, the Contax 139 Quartz has the smoothest film advance I've come across.
I also own an X-570 (X-500 in Europe?) and I prefer it overr the X-700. I can live without the X-700's program mode. Where the X-570 excels is in manual mode. Both the shutter speed dial and the aperture ring are fully coupled with the meter, unlike the X-700. So, for an atavist like me, who prefers using cameras in manual mode, the X-570 is much more fun to use. Another plus for the X-570 is it accepts all the accessories that the X-700 does, like the MD-1 motor drive, for example.