It's hard to imagine a more popular tomato than Brandywine. I don't know that there is one, especially among heirlooms. Many have considered it the best-tasting, or among the best-tasting. Although Brandywine started out as a single variety, the term without any qualifiers is now, in my opinion, quite ambiguous, and it's hard to say that your Brandywine is the same as someone else's unless you got it from the same store, or unless you know which particular strain it is. There are lots of strains. If you know the strain, please always say it as part of the breed name (instead of just saying Brandywine).
I had a friend who grew Brandywine in 2014, as well as one other variety. She gave me some unripe fruits, which I think were Brandywine, but they may have been the other tomato (she said the other tomato was striped, and these were not striped). Her plants were prolific (although she said they took a long time to ripen). Her fruits were orange-ish red to my eyes (some people appear to call that color pink, and Brandywine tomatoes are actually supposed to be pinker than that), and were beefsteak-shaped to a more smooth shape. They tasted pretty great (after I let them ripen), and they had lots of seeds. I grew some of those seeds in 2015 (a plant from each fruit shape). The fruits I grew looked similar, but they tasted a lot different, and they weren't as prolific (it was a bit of a disappointment).
Most of the Brandywine types I've tried in my garden haven't tasted terribly great (and many have been mealy). I think they must prefer warmer soil or something (ours is a clay/silt to clay/silt loam type, which insulates well, and has a habit of staying cool). I think my friend grew hers in straw bales. However, Brandy Boy F1 and the cross of it that I'm breeding with, have done excellently, and tasted great (granted they had black plastic to warm the soil). I'd like to try Brandywine again with black plastic, some day.