I'll add another reference point. Our 351 weighed 11,402 as shipped and at the last visit to the CAT Scale showed 12,780. We pull with a '13 F350 CCSB SRW and 2WD. If you put many miles on the new combination I would expect you will be happier with a diesel.
As far as drivability I find the short-bed pretty good, the turning radius is HUGE and the CC and SB is long (not as long as a LB tho). I'm surprised by the MPG which is 12-13 in the city and 20 on the highway. Towing on the highway I see 11-12.
I've always been a Blue Oval guy but expect you'd be happy with any of the big 3. I can say that my 6.7 is an OX and it loves to pull.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks