Congrats on the truck.
I too faced that choice a couple of years ago, but went with the F250.
It is also my daily driver.
The marginal extra cost of gasoline (or diesel), for a smaller, slightly more efficient truck, versus a heavy duty truck is something on the order of $80 bucks a month. At least, according to my calculations. MPG difference is 2 mpg more gas usage (less efficiency) on the F250.
The F150 was actually more expensive than the F250, because they are more popular and generally more heavily optioned.
But, nice truck for 53k. It had better be nice, for that amount of money. Heh.