I think San Marzanos have more taste but that's subjective and also based on the season. Canned tomatoes are frozen in time. Right now, the supermarket Romas are probably at their peak.
I have had cow's milk mozzarella and buffalo mozzarella. They taste different and are both good but I am perfectly OK with cow's milk mozzarella. It's like wine. Is red wine better than white? Even if you pick one, what was best might not be next year...or next bottle.
Store bought fresh vs. canned.
I will say making sauce from fresh romas is a softer more subtle and fresher taste. It's also more work. You have to ripen them and then steam/boil them to remove the skins. I core out the stems and seeds. The chefs on TV seem to throw the whole thing in, stems and all. Canned Marzanos may still have skins as each can can vary in quality. I like to dice half of the fresh ones and puree the other half. When I buy my Romas, I know what I am getting. That said, I don't always know what I am getting because sometimes store bought romas have no taste.
A typically use La Valles which are DOP and Centos which are not. I came across another brand in the store which I need to try. I avoid American made canned goods due to the possibility of BPA in the can liners. The Euros have banned BPA.
To be honest I have used San Marzanos almost exclusively for so long that I can't even remember what "plain ol'" canned tomatoes taste like on pizza.
I make my own yeast dough from scratch with Antimo Caputo tipo 00* flour (blue bag) and I do a 3 day cold rise. My sauce also contains salt, pepper, basil, oregano, garlic and red wine vinegar. Caputo is an Italian company but some of its flours are actually American grown.
My toppings are usually pecorino-romano, mozzarella, mushrooms, red and green bell peppers and red onions...and of course tomato sauce. You have to go easy with the pecorino and it's very tart and can overwhelm the pizza if you use too much. And of course, you will have a nasty body odor if you use too much garlic. Garlic and onions are also prime instigators of IBS, irritable bowel syndrome.
So the answer: To me they are worth it. To somebody else, maybe not. To somebody else, the idea of eating pizza without buffalo mozzarella might be unthinkable.
- Tipo 00 just means the flour is milled very finely...not coarse. You wouldn't use Tipo00 for say...Irish soda bread but the flour could be milled to Tipo 00.