They are on the pricey side but I am sure they are nice. I will in the near future need a cruise control/throttle lock because of damage in my right hand from over use. Was is a easy install? Stock grips?
Very easy install and I dont have stock grips, most any size grip seems possible since they do give you an assortment of shims. I like being able to take my hand off sometimes also.
At first I looked at it and thought it was not going to be easy but was never good at following directions.

just started and it all and it pieced together nicely, easy adjustment also.
About the only negative is speed does change obviously, up hills and in strong head winds otherwise consistent within a couple of mph. The trick with throttle bosses (palm rest) & locks, is to adjust them as loose as you can (just tight enough to hold when hitting bumps), then leave your hand on (covering) it, but with a greatly reduced grip (than holding against the return spring). You still have your hand covering the throttle, and small changes to increase or decrease speed, you
just twist the throttle up or down a bit against the loose lock pressure (without releasing the lock). Yeah, it's nice to give the hand a rest and just hold it down to your side, or drink your water, or wipe your face, but otherwise, just cover the throttle with little grip exerted.
At least that's how I do it.