I am definitely no expert on the matter, but I´d say it depends on how they´re grown. When I first saw tomatoes in Venezuela, I thought " OMG! Wonderful, red, ripe, sweet tomatoes!" - and was disappointed. they grow too fast.
My dad used to grow tomatoes in a greenhouse in Kent, UK. they´d ripen very slowly, but were absolutely deliciously sweet. I ate huge "heirloom" tomatoes in Italy and Greece -again, sweet and juicy.
Hydroponic tomatoes, in general, I always find a bit lacking in flavour. I cut them open and sprinkle them with a little salt before eating them. That tends to improve the flavour.
I just bought some miced cherry tomatoes from Kroger, including some greenish-purple ones called "kumate". They´re wonderfully sweet, although the skin is much tougher than the red/yellow varieties.