I grew up in Puerto Rico and although my circle of friends were all into video games, not a single person had a Turbo. It did, however, have a sizable retail presence in big stores such as Toys R Us, back when they had those cool display cards in the aisles. Being a nerd since I was a kid, I was fully aware of all the games in the Turbo library, thanks to EGM and Gamepro, but like the majority of middle class America, could not afford but one system at a time.
I do remember seeing a couple of kids at restaurants, shopping malls, etc., hauling around their Turbo Expresses. They always had the look of rich spoiled brats to me...
Interestingly enough, the Sega Master System was much bigger back home than the Turbo ever was. Not as big as the NES mind you, but a pretty sizable minority of kids I knew owned one.