These 21's look GOOD.
These do NOT. Just my opinion of course - but 21's are only appropriate with the right design. snzuloz and a a few others have done it right. Everything else looks awful - too hood, too *******, or just tasteless.
Sorry if that's not PC, but those are the only terms I can give you to describe how it might play out. I'm with the other guys - even my 20's seem to compromise the ride a bit and don't really offer much more in performance. But there are a ton of good tires out there in the 305/30/20 size that I'm running out back, including some great track tires and drag radials. So I went with my setup based on the wide range of tire options I would have and gave in a little on the ride quality. But I'd never go to a 21 or 22 - there are hardly any good tires available in sizes above 20. There's a few, but not many. And prices are ALWAYS at a premium because the tire makers know guys running 21's and 22's are addicted to them...