I finally picked up a G2 Throttle Cam from KTMtwins.com. The 990 has a pretty twitchy throttle, especially at low RPMs. Rolling 'on' and 'off' throttle, just at that transition, the bike can really buck around -- this has been endlessly discussed in the Orange Crush forum at advrider.com, and a lot of people said the G2 helped. I'm using the '400' cam (marked "K400" on the cam itself, but also referred to as the "G400" for whatever reason).

I've found that the 400 cam really helps -- the twitchiness is still there, but reduced. I think it's also really important to tweak the throttle cables when you install it. If I left a little 'dead spot' at the closed position, that seemed to help a lot. When I tightened it up so there wasn't a dead spot, the bucking returned. A little bit of slack when the throttle is closed seems to really help buffer the closing phase of the throttle, and it feels less like the throttle slams completely shut. After tweaking the cables while riding around for a couple hours this morning, I'm really happy with the outcome -- smooth throttle response down low, and it rolls nicely into the tons-of-power throttle phase, which everybody loves. I'm back to wanting to ride this thing all day every day.