The NSR was designed for 60+hp and then restricted to 40~45hp depending on model.
The MC28 is expensive to derestrict because of the HRC card, and in my opinion they never seem to go quite as well as the MC21 even with HRC help. That's in road trim anyway, airbox, filter etc.
No aprilia that I've ever seen gets anywhere near 75hp. It's pretty much a Suzuki lump. We saw 63hp on the Suzook and 64hp on the Aprilia. Both with race pipes and a bit of setting. Neither felt anywhere near as good as the 63hp NSR MC21 we tested against.
Standard gearing works quite well in town and is good for a shade under 200kmh when derestricted...probably.