Has Tormek considered a model with both the standard stone and a Japanese stone replacing the leather honing wheel? Since you do not need the leather hone with the japanese stone, such a model would be something I could use. Changing wheels is a pain.
Water cannot be used on both sides of the machine, and the leather honing wheel is quite useful even when a SJ-250 is present. I suggest you look at the new EZY-Lock shaft, which makes changing stones an effortless, tool-less step.