Jabby:
I had the same problem as you. I loved the F250 and wanted one really bad, although I was only going to tow an 18ft trailer and tractor 3-5 times a year. I drove a F250 with a 5.4L. It was a dog. It would not move out of its own tracks. It would not slip a wheel on wet pavement. So I drove a second F250 with the 5.4L, same diagnosis, total lack of power. I can not comment on the V10. I then drove the same truck except with a diesel. (NOTE: All three trucks were at the same dealer, and test drives were on the same day.) What a difference the diesel made, lots of power.
My current research indicates that the MPG on the F250 with a 5.4L will be about 11 to 13 MPG mixed driving with no trailer. Towing will be a lot less with a 7000 lb trailer and the V10 will fair no better than the V8
I Got a F150 5.4L. It will do…