Cruise assist lever
pros-very easy installation. Reduces the wrist fatigue on the long highway runs.
cons- gets stolen easily
I would suggest that those are dangerous: when turning in a tight circle (at very low speed) to the right a "cramp-buster" can trap your hand causing the revs to rise, and down you go. Also, IF you get out-of-control in a situation, sometimes you can't reduce throttle (you're holding on too tightly), so, again - down you go.
Neither of these is theoretical.
On my first Alaska adventure my partner was visiting a buddy in Anchorage, going up a steep drive when he realized his buddy lived next door so he attempted a U-turn, his hand trapped the "cramp-buster", throttles opened and his 104 HP B1200S threw him down, pinning him UNDER where he had to stay till someone came looking for him, and helped him lift the bike.
Riding dirt roads near here two years ago, my buddy (DIFFERENT buddy!) was going faster than I thought was a good idea, he was leading, when he went wide on a corner and into the soft sand on the shoulder. His bike was 'fish-tailing' back-and-forth, clearly out-of-control, the "cramp-buster" keeping him from reducing throttle, and he hit a large rock and went over the handle bars, luckily not breaking anything on HIS body, tho' he did break the crankcase and had to be towed.
BOTH guys chucked their "cramp-busters" as far as they could throw them.
I use a Vista Cruise Universal on my bikes BECAUSE you can increase or reduce throttle easily.