the only time i use mine is when i am jumpstarting other vehicles and on a steep climb to keep revs constant other than that may be on a long trip for a short period to give the foot a rest but would never use it as a cruise control because of obvious reasons already stated plus it would cause to use more fuel than is requred especially on a down hill
I always use mine for the first start of the day, otherwise the truck runs rough like a dog flicking the water of its back. Have also used it on rough stuff but never on the road, I prefer absolute control when I'm driving. Always called it a choke too. Just started snowing tonight so guna need it in the morning before work lol
Originally coming from a cold country, I've always thought this was only really for use when you're starting a cold engine on a cold day. This brings back memories of trying to start 35 year old tractors in -15. From getting in the cab to driving anywhere could take us anywhere up to an hour, hence the hand throttle
That is what I use mine for.