Well all I can tell you is that this is the first Honda I have owned so its not like I would buy anything they make just because it is a Honda. I am not looking for a RZR type machine... honestly if polaris made a 50" ranger I would have looked very closely at it, I would not be surprised to see Polaris make one now. The rear bed on the RZR is tiny/really high off the ground and it just feels like a mini dune buggy to me, not what I am looking for. I wanted something that is easy to get in/out, affordable, quiet with good reliability, can haul a deer out of tight woods on a rack that is large and a very usable height, can take to the local ORV 50" trails with my 6yr old son and have some fun, and do some work around my property. It fills all those needs perfectly, the unique transmission is a great bonus as well.
Now maybe I am the only customer with those needs but I doubt it. I am not interested in racing down washboard fire roads, jumping berms with 10" of travel. You are looking at the market from your perspective, there are alot of people out there that can have fun without a sport machine. Perhaps Honda will make a 50" sport machine for people with your interests, it looks like Yamaha is about to release something like that, so RZR competition is coming.
Aso, p500s are very low geared with plenty of fender clearance and can handle larger tires with ease. I have not heard anyone mention power issues with 26,27, or even 28 tires.