The skinny (2.15" wide) 21's will generally offer a little more twitchy feeling on the road, especially if the road has grooves. Those skinny tires really love to follow them.
If you want to keep the handling/steering feel you have now yet get the look of a 21 out front, look for a 21x3.25" wheel. Most every aftermarket wheel maker offers them, and they're just a hair more than the skinnier one. This mated with a 120-series tire IMO is the "best of both worlds" solution.
, I happen to have NIB 60-spoke 21x3.25 3/4" axle single flange wheel sitting here if you'd be interested. Paid $150+shipping, but I'll let it go for $100 + actual shipping.
Have a matching 18x8.5" rear wheel and brand new Dunlop Elite 3's for both as well if you're interested (tires are 120/70-21 and 250/40VR18). Will make a good deal if someone want's the whole kit & kaboodle.