I did flat spin recovery training with Genna in our Yak 52 a while ago. The effect of power on and power off in an aeroplane with a heavy and powerful engine is quite marked - far more so than in, say, the Chippy.
Agree with BEagle that the POH is king. And while far from being an expert in spinning, I have a suspicion that the dynamics of a spin can be more complex than most of us realise, with a potential for the unexpected to happen. So perhaps they should be treated with even more respect than other aspects of flight.
SSD