IMHO it makes the throttle on/off transition more positive with no built in ambiguity. Granted the spacer isn't cheap for what it is but it's well worth the cost. Disconnecting the exhaust flapper valve is also a worthwhile mod if you haven't already done it. It's just there for noise emissions at the specific revs that the legislation calls for, in effect it's a cheat device. From my experience it messes with around town speed riding. Unhooking the cable, adding a spring to add a little tension and wiring the flap open is practically free and makes the bike more pleasant to ride at lower speeds.
Yes. The bike can hunt a little and whilst it does not cure that, makes the throttle more predictable. Ultimately personal preference, but I much prefer it with the spacer.
