For your weight and given the fact that you lean more towards the park (wait, I'm assuming that, you didn't say it), the Rossi will be a better ski for you.
Regardless of my assumption about the magnetic attraction that the park has on you, here are my thoughts: The P4's performance leans more towards big mountain skiing than the BC. The BC is a bit more nimble and given your weight, will be less effort to ski (less effort = more fun). Not that the P4 is a monster, but definitely more of a big turn, haul ass, deep snow ski IMO, particularly in the 191 length. The rossi is a bit more versatile and will definitely be more fun in the park.
Not that it matters, but I own both the BC and the P4 and ski them both regularly (skied the P4s yesterday, in fact.)