I prefer the 13/14 over the earlier ones. I like the dash, nav and headlight more... it's all personal preference. I bought all of mine from out of state from different dealerships... I doesn't matter what dealership you buy it from, it's more if the truck is what you want and the ease of working with the sales guy. Take a look at a 12 and 13/14 in your area to see what you like and dislike on them.
I bought a low mileage, supercharged 12 from a Mercedes dealership in Houston in 2017. My cousin worked there (not in sales) and got me a great deal. He had a sales guy contact me to do the sale and he was fantastic to work with. I flew in late and stayed at his house. He had the truck at his house and the sales guy came over that night to do the paperwork so I can leave in the morning. I bought it based of off his word and pictures he sent me. It was a trade in from Dallas. Once he got it in and sent me some pictures, I put a deposit on it. It was a great deal, low mileage and I always wanted a supercharged truck. They did an oil change on it before I bought it and gave me a full tank of fuel.
I bought a 13 from a Ford dealership in Montana earlier this year. The guy ended up getting me the price I wanted (a few hundred bucks off), but he was very pushy until I gave him a deposit, then he became very unresponsive. I got it for a really good price given the options and low miles on it. He knew what he had on the lot and knew what he could get for it since it was at a Ford dealership. They didn't have any pictures posted for it online. It was a local trade in that came in a couple days before. He sent me all the specific pictures I requested, but he "forgot" to mention some stuff about it or take pictures of those areas. When I got there and saw it in person, I wasn't happy about a few things, but again, the price was good and it fit my budget and needs/wants. I flew up there and got in at night. He brought the truck to me at the hotel in the morning and we signed all the paperwork there and I took off. Sad part is, it barely had any fuel in it. He said they don't put fuel in used cars. I was kind of annoyed with him at this point, but at least I had a truck again.