If you live in the flat lands the Honda 500 would be fine, but a 500CC side by side with two people and gear climbing any steep terrain with NO low gear is going to be a gutless pig. The only Honda sxs that has low gear is the 1000, the 700 while it doesnt have low gear either at least has a little more power and can get the job done a little better but the 500 will get its ass kicked doing any real work in terrain.
Note....the 500 is geared. I think it will have the umph needed for 2 people. Maybe not speed but Honda's first gear is tractor-like.
I should add I don't drive a Pioneer but use a Foreman everyday.
