This really comes down to personal preference & riding style. I had and sold a WRR. Just like any other dual sport bike, it was a mix of compromises. For some people, that mix will work, and for others it won't.
I found the WRR to be down on power for agressive off roading. That's not to say it didn't do well for what it was, but the laque of tourque was tiresome, and I didn't like the bike's inability to get the front end up at speed (like, say, when approaching a log crossing and you don't want to slow down). Don't get me wrong, I could go anywhere I wanted on the bike, but I could never come to grips with the lack of power. That being said, a big 650 like the KLR would have been far worse.
Contrary to what others seem to thnk, I did not like the WRR on the highway at all. It was a fantastic back roads bike, and was a joy as long as the speeds were >65ish, but maintaining anything above that was a battle if you were going up any kind of grade. Yes, it would run 75, but you had to keep it pinned and shift to keep it there. I did several 100+ mile pavement stints on the bike, and it just wore me out. I would have much prefered a KLR/ DR/ Dakar 650 for that kind of thing.
I ended up with a KTM 525 for my "daul sport" use, and will eventuall compliment it with something along the lines of a KLR. For me, the KTM works far better. There is no comparison off road, and it handles limited pavement duty about as well (with alot more power on top). It fits my style and needs. BUT, if I rode less aggressively, or was looking for more of an "exploring"/ plodding around/ forest service road type bike, I would have kept the WRR.
In the end, you almost have to have two bikes. I agree with a previous poster who reccomended keeping the KLR and complimenting it with a low priced, taggable dirt bike.