Interesting that he mainly grows the larger tomatoes, I've never managed to get them to produce well for me. Cherry tomatoes, on the other hand, will do well for me. I'd say it's the amount of sunlight, but my parents' garden in San Antonio had FULL sun and we had the same problem there. We'd get some large tomatoes, but the cherries just did SO much better that we gave up.

My experience is the same as tx_ag_95 - my super sweet 100s do very well, my beefsteak plants, not so much.

Here is a link that might be useful: My tomato experience