Some years, some heirlooms do great for me. Some years, they don't. Some years, some hygrids do great for me. Some years, they don't.
Last year was a horrible year for tomatoes for me. Nothing did well. It was just too hot and dry, mainly hot. I watered. 4th of July and Big Mama hybrids produced some. Goliath hybrids did nothing. Box Car Willie and Park's Whopper open-pollinated produced a little. Black Krim and Mr. Stripey, open-pollinated that usually do OK here, produced nothing. Don't get to hung up on heritage and hybrid. It's the varieties that do well in your area and the growing season you happen to get that counts a lot more than whether they are hybrid or heirloom.