Their previous models of Formula 1 cars were not well thought of by people who ran Ninco, Scalextric and SCX cars and much preferred them. To be fair, I am not sure that many (UK or USA) people had proper hands-on experience of the Carrera F1s and it could be that the reluctance to buy them was partly based on slim availability - at least in UK, coupled with the notorious bias displayed by some voluble board posters. I think the criticisms of their F1s were similar to those levelled at many of their other cars - too low a numeric gear ratio and low magnetism. In practice, these characteristics could be an advantage over the others on a big enough track, where the extra top speed could actually be achieved!
I faintly recollect someone suggesting that the gears were a little fragile too, though I cannot be sure of this.
This is good question, because I don't know whether Carrera has yet reissued these cars with the new gearing as per the F1 Ferrari, nor am I sure whether they intend to do so.
Has anyone else more useful and up to date information to add?