I don’t grow tomaters and the heirloom ones I have bought were disappointing. Grape and Roma are better, but canned is very consistently excellent. Don’t say that about many foods.
The San Marzanos make ethereal sauce when cooked, regardless of whatever chemical description. Rao’s restaurant only uses them. The mystique comes not from the provenance of the tomatoes. It is that Rao’s has served great food for generations, is small, has generations of customers who crow about it and its exclusivity. They have a policy of saying “no” to very successful people (which they enjoy) and so has acquired a reputation as one of the hardest lauded restaurants in the world to eat at in person. People years ago bought the right to eat there a couple times a year, I think I recall, and these “dining rights” are considered as rare and valuable as old-fashioned taxi licences.
I can’t fairly comment on their sauce, since I haven’t tried it (or even seen the Bolognese). I doubt it would contain the same hefty amount of meat I use in mine. Fresh is certainly better. It’s not hard to make great Bolognese. The recipe in Rao’s, which one assumes is better than the commercial version, is pretty traditional. Not a lot of added sugar or chemical crap. How much does it cost in the States, normal price and on special?