What is the difference in taste between San Marzano and 6 in 1 ground tomatoes? I've been looking at some recipes for Chicago style pizza recently, and the consensus seems to be to use 6 in 1 ground tomatoes for the sauce. 

Generally, when I make sauce, I use San Marzano tomatoes. How would that affect the taste of the sauce?
I would guess that the difference is negligible, especially if you are making a cooked sauce and it is the ingredient in a Chicago style (I assume deep dish, lots of toppings) pizza.  You might be able to taste a difference in a side by side comparison of sauces, but even then the difference is likely not going to be critical for any final product.