There is the lighting bending that can mess the speed a little : if you believe that reacting to lightning is an hypersonic feat let’s go. If not Avatar overall speed is quite lower.
but lets say we equalize speed Avatar state Korra or Aang are quite strong.
Korra managed to stop that
and Aang should have the same power if not more : more experienced etc.
Max power Teen Aang can destroy Ozai and Adult is even stronger.
With Equal speed I can see Adult max power Aang being as strong as some strong post skip charcaters. When you see what past avatar can do etc its crazy.
With speed unequal Aang can protect himself with an air shield in Avatar state and that shit can take hits. But he will have to bet on AOE to catch the faster opponents he will have to fight.