In my garden I have all kind of tomatoes, from cherry tomatoes to Tasty Toms and Pommodore and several wich name I don't know because they where give aways. But they all tast great and sweet even taste better then last year. Did your tomatoes catch enough sun and warmt? Tomatoes don't like watering from above, alway water them by their feet. When its very hot they must have a lot of water in the morning and in the evening.Tomatoes does like to be in the area with asperagus and beans (but mine are also near the corns)and they do also like a metal stick to grow at, not a wooden. Tomatoes don't like to be touched with smokey hands.
I don't know whats going on with your tomatoes but maybe these tips will help a bit. Oh and I never use hybride seeds because I can't use that seed again for the next year.