Having had a number of each, my opinion....and it is my opinion only, the best, smoothest, and most reliable are the German multi-lever double sets as found on the old Scheutzen rifles. I had a Johathan Browning mountain rifle with single set and it didn't seem to want to hold to a uniform pull. I had a Krikko rifle with double and it was wonderful (.222). Dixie doubles I put on a couple rifles were "o.k." but not outstanding. The TC doubles, even the reverse acting one on the Patriot are all fine, smooth and reliable. Only problem with any of them is the "click" when you set it while hunting....I know, there are ways to get around it but I prefer to shoot unset while hunting (and practice also).
After all that...my vote goes to double.