Ok, so aside of the 496 vs. 525 question, have you asked yourself this... How long to you plan on keeping it for? Are you going to get 3'-itis, 6'-itis or more... or will you just be good with 27' and want to keep it for 5-10 years? I would think the 496 w/ the ext. warranty is the way to go if you plan to get rid of it in the next few years, less money out now - better resale down the road.
Either way - nice choice, great looking and running boat no matter which motor you go with.