I rarely use the third wheel. I thought I would use it for ISO, but find it hard to turn it with my thumb only. Much easier to do that the old way. On the rare occasion when I want to toggle the SR, though, it's easier to use the wheel than any menu. I suppose crop mode could be a candidate, but then I prefer cropping in post anyway - and I rarely need the higher frame rate. User modes would be great (if there are good options to fill the modes with).
All in all I think I'd prefer a larger LCD panel instead, but just as the disused video switch on the K-3 doesn't bother me much, neither do the extra wheels.
They do make the K-1 just a bit more special