Hi Juan!
I'm growing 5 different kinds of tomato this year. None of them are Juan's STARLESS because I messed up and didn't save any seeds. Based on the trouble people have been having with them I suspect that it is a hybrid that is breeding out. You never know what genetics you are going to get from one generation to the next.
I know people are big on heirloom varieties, but there are some great disease resistance hybrids out there. I've been growing Jersey Giants and San Marzanos for canning, both are open pollenated (heirloom). I decided to get away from the Jersey Giants and try a hybrid that is bred from it. I like the way it is performing so far. The San Marzanos are already showing some verticillium wilt, which is a reason to get away from them maybe in the future.
The little tomatoes are "4th of July" and they are early. They were ready by maybe July 10. The flavor is fantastic, with nice acidity and sweetness. They are small, about 1 1/2" in diameter and have a lot of seeds, so they aren't good for much other than quartering and eating with a bit of salt, and they are tasty that way. They are shown here with a 3" Garden Treasure for scale.
I tried a variety called "Garden Treasure" for slicing tomatoes and they are fantastic. Meaty, 3 to 4" diameter, with good flavor. Great for sandwiches.
I'm growing two varieties of roma style tomatoes this year. The smaller ones on the right are San Marzanos and the others are some highly touted hybrid that I thought I'd try. Both have small seed chambers and a lot of meat.
I dropped Jersey Giants from the lineup and tried these "Big Mama" hybrid from Burpees. So far so good. They are smaller than the Jersey Giants but ripen more evenly and the plants are more healthy. They have the same small seed chambers which make them good for canning. Shown here with a San Marzano to show size.