My bike came with a damper, ripped it off and sold it after a month or two.. Not necessary unless you're a total spanner/track day junkie. I'm a bit of both but not enough to warrant a damper
Are you out of your mind? No offense, but you're kinda dumb if you remove part of your suspension. And yes a damper is part of your suspension when you are leaned over. Don't hand out bum information that could get somebody hurt such as removing pieces of your suspension. There's a reason dampers come stock with most bikes now. Suspension geometry is aggressive enough that it makes the chassis' unstable while leaned over, hence the factory installed dampers.
A Scotts damper was the single most valuable piece of safety equipment that I didn't wear on my body. It saved my arse a few times... even on my rock-solid RC51. And you don't have to be dragging your knees to benefit from it. You can be just going around a normal street corner and hit a patch of sand/dirt while on the throttle and go into a headshake.
lanbrown and Idavis are right. Don't get a cheap model. Just save your money and get a quality dual-valve model. $400 for the Scotts and worth every penny. It doesn't have to be Scotts, but make sure it is a dual-valve. It has separate high and low speed circuits. On a street bike you only really need the high speed(for headshake), and can turn down the low speed for easier street riding(U-turns, driveways, parking lots, heavy traffic). Once you set it up after a few hours of testing, you never touch it again.
With the single valve setups(90% of all dampers), you have only stiff to weak damping. So the optimal setting to minimize headshake makes the steering too stiff to do normal riding on the street. And the best setting to make street riding enjoyable defeats the purpose of having the damper. Although this type of damper is perfect for track/race use, they are the same price as a dual valve damper, so why bother with this one?