We are in preliminary stages of maybe?? going to a Phoenix Cruiser also. I have yet to hear about any glaring quality issues about them, at least in the models from the last 7 years or so. I hear from current owners that the company is easy to work with and is willing to make changes to equipment and floor plan changes within reason of course.
I would also go for the 450 chassis for the reasons mentioned above by dittmer & mlts22. The extra 2k or so cargo capacity never hurts in the "toughness" quotient, along with the hydro boost brakes and the 4.56 gear ratio.
Edit: I recently sent an inquiry to the company via email, and it was answered by the president of the company within an hour