Just got back from a weekend riding mostly on unsealed roads and foresty tracks (with a few creek crossing thrown in for luck) through northern New South Wales on my XTR. Had a friend with me on an XTZ and another on a TE510 Husky. With all our gear for the weekend loaded in panniers both XT's did great. What really suprised me was that the XTR was just as capable as the XTZ. As mentioned, the only real negative to the R is lack of protection and ground clearance as stock. Other than that, they both perform as well as each other off road. Thr R suits me because 99% of the time i use it to commute, but when i do take it off road it can keep up with the best of them and carry all my gear. The Z does have better suspension with adjustable forks which would be nice on the R. Engine feels smother on the Z but I guess that has a lot to do with the hugs bar end weights. Also has twin disks on the front so it can stop pretty sharply when it needs to. If your going to sit the bike in the shed and bring it out on weekends to go adventure riding, the Z is the bike for you. If you want to use the bike day to day on the road and take it off road now and again, the R's the answer.