I have driven both Kw and Petes and there is really no difference in them as far as the way they drive,but like all trucks there is a difference in the way they ride.They are both built by Paccar.I guess I would have to say I like a 379 Pete more than a w900 KW.
I have almost 4 years in a 379, now, and have also driven W900's. I think the visibility of a W900 is better when in tight spots, especially to the right side front corner of the hood.
I like my 379, but would gladly drive either.
What I don't like about the 379 is the way they have set up storage in the sleeper. If you don't have the extra cabinets across the back, it really cuts into how many nooks and crannies you can put stuff in. The W900 seems better set up for storage.