The bottom line is: if you don't need/want the small size, there are indeed much better (and expensive) options.
It takes significant money to turn the P5 into a viable trail machine, IMO. Tires, front locker, shocks, skid plate, etc. Plus roof, windshield, rear panel, etc. for comfort . . . $5K, easy.
But the fun, versatility and challenge factor is what I absolutely love about this machine. I'm getting better and better at driving. Lots of different lines to choose from. I've seen folks with large machines: A. with nowhere to ride them without trailering them or B. searching out difficult trails because otherwise they'd be bored.
Just really depends on what you're after . . . I need the small size for where I use it, and now I'm glad I run the small machine. I'll lose my nerve before it loses its' capability!