Yeah, I did one a couple of months ago. Once my truck came in, I ran around to some local lots to see what they'd give me for my loaded 18 Laramie 2500 CTD. Once I had those, I emailed a bunch of pictures of my old truck to Granger (there is no "i" in Granger, BTW). They shot me back a trade in price that was lower than one very generous local cash offer I had. So we negotiated a bit and they got very close, and I took the offer. It was worth it since Granger is 7 hours away and being able to drive my old truck up to trade was easier and cheaper than having to get the wife and dogs to do a road trip. Here in Arkansas, I don't have the trade in gap tax issue. I can sell private party and as long as it's within 60 days either way of buying a new truck, the state gives me that credit on sales tax. But still, it was more convenient to trade.
Once I got there, it was no hassle. They did a quick inspection of my old truck to make sure it was the same as I said it was, but no other talk about the trade price. They honored it. I was in and out of there in like an hour. Very happy with the entire process.