Well I finally got around to testing my new dirt wheels (mounted with Dunlop 606's) for my X. First ride was on the pavement, in the rain, on fresh knobbies. It wasn't pretty.....
. Anyway, the point of this is after a few hours testing the new setup (no suspension adjustments yet but some are definitely needed), I came to realize how well the 17" wheels work. They really make the X into a totally different machine from the R. Traction, stability, and WAY less gyroscopic affect from the smaller front wheel (and getting rid of those squirmy knobbies) make it work on the road so much better.
I need to do some suspension tuning but once I get there, it's going to be nice to have both wheel options but if you are an R owner who spends a fair amount of time on the road, you need to beg, borrow or steal a ride from an X owner to try it out. You will not regret having a set of 17" wheel for your bike.