So I took it out for a test ride. There is good news and bad news. It seemed to work at about 60 mph, but I can't say for sure HOW I got it engaged. It seemed slow to 'catch on', but it held speed for time even up and down slight inclines on the interstate. I COULD NOT get it to engage below 50 mph. I don't know, but it seems to be kind of slow on the uptake even on the interstate.
I haven't figured out how it actually engages. So I can't positively say that it is working correctly. It does disengage with the brakes (both), clutch, and the off switch, so that part is pretty good. I'm just not real certain about activating it. There were times that I hit the switch and it just activated. There were times that I pushed the set button, nothing, pushed it again, nothing, then pushed again, and it worked. Other times it was just like in my truck, hit it, and forget it.
So I'm not sure what is going on. I'm going to keep playing with it.