Interesting, I've never heard nor had this complaint before. Last thing I'd ever describe the KJ as is sensitive or go-kart like. I guess it's all relative.
Your tires will play a big part, as well. The OEM street tires I had were actually pretty good for on-road performance. Then I bought my yoko's and my off-road performance increased dramatically, but now my KJ 'hunts' on the freeway with the natural grooves on the road.
It's a little aggravating, but I'll live with the slight on-road dip in performance for the significant gains I made in off-road performance.