When it comes to fresh vs canned tomatoes, even the Italians frequently use canned. They are often riper, richer and sweeter than the fresh you can buy in shops. Different if you grow your own to ripe perfection before picking them. I much prefer to buy whole plum tomatoes in cans. Cirio and Napolina are good brands, but there are often annoying bits of skin and tough bits of blossom-end rot/greenback in both which I cut out. And I never leave out that pinch of sugar. It sounds wrong but it miraculously improves the flavour - even the Italians do it. Rachel Roddy always does it! I hate skinning tomatoes. When I make salmorejo in summer, my very favourite tapa, I blitz the toms with skin on. It works for me!