That's interesting ... Better MPG than I thought you'd end up getting. What were the specs on the "larger" trailer? It's currently over GVWR and that's before I hitch a trailer to it. The 250 would afford me a longer bed, more payload, better towing (as it looks like that's something I'll likely do more and more regularly), and still do everything else I want it to while maintaining decent reliability.
I'm not 100% sure on the specs, tbh. It was a rental from a private owner. Originally I wanted their 21' unit, but it wound up having a wheel bearing problem, when I returned it they let me have their 23' unit instead, plus they threw in a generator for free. All told...3500# or so?? I didn't weigh it, to my regret. The Raptor tends to run pretty rich when you're in the boost to keep the turbos cool, so that can tank mileage pretty quick. I could definitely feel it behind me, but never did I feel like I didn't have enough truck to handle it. A weight-distributing hitch can go a long way to making eh ride more comfortable for you and the truck as well. You pointed out all the advantages of a 250. If you're at GVWR on the Raptor, and decide to tow, you'll need to move cargo to the trailer, but still stay below the GCWR, which might be a further limitation. Maybe a 250 Tremor would be more to your liking. I read the comment earlier about the 6.7 diesel being a good choice in their opinion, and they do have a certain appeal. If you gut a good one, your probably set for whatever you'd tow...1000+ ft-lbs of torque after all...but if you get one with issues it can be one headache after another troubleshooting them. Although, if you're going to get a 250, maybe consider going all the way up to 450...not for cargo/towing capacity, but with the wider front axle on the 450's you cut down your turning radius, and if you do go into the boonies that is a consideration.
If you have a good relationship with your Ford dealer (Curious who you bought from), they may let you take a diesel on an extended test drive over a weekend, that would give you a chance to really get to know if it's right for you or not (comfort, size, features, etc). Probably not the exact one you want (nor a Tremor) but enough to give you a solid idea of what you'd be getting. Last thing I'd want to see is that you pull the trigger, then some time later have buyers' remorse and miss the Raptor.