If yer looking for a 18K hitch ya won't find it in a Curt. I just purchased a Q20 Curt last week and they only make a 16,20 and 22K ones that I've seen.
The nice thing was at the "Hitch House" where I bought it and had it installed they had multiple others on display as well, most comparable was the Reese. With the 2 side by side the Curt was hands down the winner! It comes in a more compact but beefier design and the fact that the head still has the swivel but on a semi ridged mount made the sell. The Reese head moves in all 4 directions but just flops around banging while not hooked to a trailer. The other BIG feature of the Curt hitches is their 10 year warranty that will outlast the truck it's in!