I have the McCruise and I don't what sensitivity it is on (it was on the bike when I bought it), but it is as smooth as. The only time I get a "surge" is when I hit Resume at about 0 to 10 km under the set speed. It seems to loag for a bit and then throttle on to try to quickly bring it back to speed, Now that I know it does that, I anticpate it and it doesn't bother me.
If the speed is below 10 it just slowly winds back up to cruise speed.
Something to watch fro is if you get someone working on the rear wheel for a tyre or servicing. they have a tendency to bend the plate carrying the speed sensor back and the gap becomes to large. If it is just large enough, it will cancel cruise when you hit a bump.
Have a safe and enjoyable trip.