Hey I love them both and could have owned a 21 many times over and for far less money too. It's a personal preference thing really and any NSR in the States is rare.
When I finally get around to rebuilding my engine.... sure I'd love to hear some tricks from you guys to gain a hp or two but it's not a priority for this bike. If I was going to be racing it, damn straight every bit counts, but for the canyons no problem just having fun.