I commend Triumph for trying to put FI on their first 600. My ZX-12R is the first FI bike I've owned, and am delighted with not having to deal with carburettors. The hassle of keeping 4 carbs clean, in tune and in sync is something that I hate more than most motorcycle related things. The biggest attraction to me is the freedom from maintenance. If the EPA is happy too, great!
I am not concerned with throttle response problems because I haven't had the luxury of trying out every bike around to see what perfect carburettion feels like. Prior to my 12, I used to own a '98 Ducati 900ss which was so badly carburetted that the bike wouldn't even run cleanly under 3k rpm. There were aftermarket fixes, the best being new carbs for $1k, but I never bothered. Compared to that bike, the 12's throttle seems SUPER slick.
I think the only people who don't like FI are the one's blessed with perfectly carburetted machines.