They are my favorite also. I never liked tomatoes while I was growing up. I now know that I am sensitive to acid in tomatoes, pineapple and citrus, although I can eat mandarin oranges without problems.
I'm told the yellow tomatoes have less acid than the red tomatoes. GladPinkie-Pepper found the yellow pears. We grew Peach tomatoes this year and I also loved them. I believe they are a low acid tomato also.