I've tried Dominos Traditional vs Pizzahut Deep Pan, and while the Pizzahut ones had a lot more calories and were slightly larger, I think Dominos ones tasted better overall, especially the cheese. Dominos cheese is absolutely amazing compared to the Pizzahut one, which just felt "okay". Going to try Dominos Deep Pan next to see how it compares.
Price wise, they are roughly the same, except that Pizza hut doesn't have the two free topping changes thing that Dominos does, so you get less variety.
Which do you prefer?
Neither, both mass produced crap.