I've used alumahyde II and gunkote. I don't know if it is the same as KG Gunkote. Alumahyde II makes a very nice smooth finish and is fairly durable, but NOT very solvent resistant! I use WD 40 or CLP to clean the coated parts and just use great care when cleaning the bore with hoppes.
The drying process CAN be speeded up by baking the gun for 4 to 5 hours at 180 to 200 degrees.
Gunkote is very tough and chip resistant, and pretty good at solvent resistance. Even lacquer thinner or brake cleaner does not have a lot of effect on it (i mean for momentary applications like during cleaning, anything of longer duration such as soaking, and all bets are off.) However i used "flat black" gunkote and it came out more like a satin. I wanted flat black , not satin, so i contacted Brownells who were nice enough to send me a new can. Same results.