Ok several notes:
1. I get PW in Yak in about the same ratio (maybe little bit more) than other planes with bubble cockpit like Mustang or Dora (usually not from dead 6). In most of cases I die because of damage to the plane and not due to PW.
2. About "climbing" I tried this 100mph climb myth. No the plane does not climb at 100 mph it stalls and start falling. Of course initial climb when you for example take a plane from 120 to 100 would be high but than the plane would stall and you'll fall. I can't hold the Yak in steady climb at 100mph with high values.
Guys... everybody who complains about Yak-3 strengths I suggest fly it for a while - your complains would vanish.
It is an amazing plane but there is no magic, it breaks apart easily from short burst, it looses parts at overspeed with very little notification, it has pathetic loiter time (actually flying 100% thrust is a mistake, it is like flying on WEP all the time) and it has very short amount of ammo so you need to be a sharp shooter - no snapshots, it has a terrible glide ratio, it isn't fast and its high altitude performance is poor, and attacking B-17 is quite a suicide in Yak-3. Yet, Yak-3 is considered one of the best fighters of WW2.
It is agile, it has good power loading and hard to hit that is why in right hands it is very dangerous.