Ive got the wider rear 17" and wide front 19" on my DR,I do think a 17" on the front is too small and changes handling too much,they look cool though. DR is no super-moto bike no matter how you slice it.
I think I can go just as fast around corners on the road with a semi smooth 21" tire on the front but the spare wheelset is very handy. Ive got Shinko 705's on my street wheels and they are cheap and work great for road or fireroad cruising.
I keep the knobbys on my stock wheels in the closet but hardly use em as I ride my plated DRZe for most off road bashing,or the 300 KTM.
Some bikes around at times