The ATV's I'm familiar all have the larger 30ah battery so that may handle the peak loads of the PS. If the charging system is constantly running @ full output to keep up that's not good for sure. I don't know if they upgrade the charging system for the 400/500's PS models or they rely on the larger battery capacity.....certainly worth exploring.
Myself I would use those dollars to an upgrade LX model, many other good things come when you upgade to a PS model. Such things as a winch, Aluminum rims, 6 ply tires etc.