Some hybrids are crosses between very similar varieties, and very little difference shows up in the F2 generation. But they continue to do the cross for some certain advantage that may not show up in all of the F2's.
This turns out to be the case with the "safeway cluster" tomatoes I've been growing. Very much the same looking tomatoes in the same shape and size cluster, but yes, a few differences I see are, the stem the clusters are on are not quite as thick and pretty, and the color does not have that extreme glossiness, but are still pretty glossy.
I don't know for sure if the Campari are hybrids or not, but I have a feeling they may be. It does seem to be common these days to develop 2 strains very similar, and key in on the targetted double dominant and double recessive traits for both parent lines to work together for targetted traits.
These breeders know they have a thorobred champion F1 and are not too concerned that F2 and beyond versions may arise from them, because the targetted traits such as extremely pretty stems, extreme glossiness, or end of season productivity of full size fruits, or other top marketting or producing traits will not show all together in very many F2 or beyond plants. Breeders can also target for hybrid vigor to only exist in the F1.
All that said, I still think it is cool to dehybridize into homegrown stable varieties what the professional breeders come up with. Some of my friends, raised in cities and suburbs, actually prefer the taste of store bought tomatoes. Ok. That's what they were raised on, it's what they are used to. To them, a Hillbilly tomato is just an ugly homegrown tomato. I could remind them ad nauseum what they miss out on, and not change their mind. On the other hand they'll never get me to eat a froggy's legs.
Dominant traits, whether they are as DD or Dr, will be expressed, but usually the DD homozygous, or double dominant, will show the trait just a little bit more. Breeders are now getrting 2 strains of the same or very similar variety, and are working both the parent lines to have homozygous DD or rr for certain traits, even if not all the traits. They then select to make sure those D's and r's are all at the right place...they can check that now on sequencing machines...and then cross them.
The 2 parent lines may even come themselves from the very same original cross. Sibling varieties.
This is all actually standard hybridizing, but only with their modern tools and planned by folks with degrees who are paid to come up with a variety that has targetted goals.
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I basically said everything twice here to try to make sure possible questions are already answered.
