I own both and while I like my 350X and its a great woods machine, I still would prefer to have an R prepped for the woods. It has better suspension and is lighter so its easier to maneuver IMHO. Both have their up sides and down sides as far as maintenance goes. When its time to do a piston in the R its much easier than it is in the X. You don't have to worry about adjusting any valves in an R and there is no oil filter to worry about with the R. I've owned an R that had the same piston in it for almost 20 years and it was ridden a lot so as long as you use good oil the 2 strokes can go a long way on a piston.
John
1985 Eddie Sanders ATC330r
1986 Monstecate
1984 ATC70 (awaiting 125cc transplant)
1984 ATC125M
1986 GSXR 750 - Keepin' it old school!
1999 Arctic Cat 500 4x4 plow machine
1999 Arctic Cat Thundercat 1000 (lake lizard)
1996 Arctic Cat Jag 440 L/C (ditch banger)