Is one a 4x? That would be the only difference that would cause entry exit problems I think. The 4x being higher. You could also use some amp steps that may be lower than the cab steps. Yes when we tried the different chices back when we bought our F350, the 250 did ride differently and did not seem to be as stable. But we ended up with a 4X due to the dealer screw up on lot inventory, and basically got it for the price of a 2wd vehicle.
We like our F350 and it is our none towing vehicle of choice for road trips. Wife wanted and we got a Cl B+ RV for here as she tired of the TT! Still have it however.