@ 115 or 118. Both at their best. Two speedy and exciting fighters where you have Donaires power and deadly left hook against Tapia’s aggression and movement.
Tapia was such an underrated boxer. His imagine and life outside the ring overshadowed his skill set and responsibility in the ring. I would pick him at these weights. A helluva fight though.
Tapia was a good boxer in his time, but Nonito was Pound-for-Pound elite. Different level of talent - and since Tapia was not very hard to hit, I could even see him sharing the fate of Darchinyan and Montiel.
Donaire was so tall, long, strong, quick and powerful, I just can't see Tapia beating him. It might be close and competitive, possibly a decision, but I think Nonito edges it even if he doesn't stop him.
Tapia was very hard to hit when he wanted to box. I like them both but Tapia is quicker and can really move when the need called for it. Danny Romero could punch and Tapia handled him very well. John Michael Johnson could crack as well and Tapia beat him. The problem is I don't know how Nonito handles Tapias speed.
Donaire was both rangier and - in my opinion - faster, so I'm not sure if the legs would be enough for Tapia. I know He did well boxing tall Konadu for example, but Nana was the type of fighter who needed to plant his feet to throw. It's different against a counter-puncher. Tapia would have to be in range for that left hook every time He'd commit. Both Montiel and Darchinyan were only stopped by Nonito in their prime - and both fought other good punchers also. Donaire was just different. When You go back and watch him around his prime, against Montiel for example - his speed is almost unnatural. Flash was the perfect nickname for him.