Last year I blogged on the advantage of using heirloom garden seeds instead of hybrids: the second generation of plants will breed true from saved seed, so you won't need to keep buying new hybrid seeds every year. It's equally true that hybrids can more disease-resistant and productive than heirlooms. Experimentation is the only way to find out what works best in your garden.
My first heirloom spring garden wasn't a great success. The bell peppers produced few fruits. The tomatoes yielded a better crop than the peppers did, but still far less than most hybrid tomatoes I've grown. The lettuce and bok choy should have been planted last fall, but the bok choy at least produced plenty of seed for a second try. The sugar snap peas and yardlong beans were stellar performers, and I'm now growing a second generation of beans from saved seed. The Suyo Long cucumbers also did well.