It depends on what your doing with it, for the amount of time you have an Elk to pull, I wouldn't buy a machine for that alone! But for the amount of time you spend just rideing, a 300 with better suspension & more manuverability may be right for you. Believe it or not I carried a calf moose ON the rear rack for 5 miles until could reach it with truck, so these machines are capable. As for speed the 500 is faster on top but can only CRUISE at 40-45mph for any distance without overreving the motor, wereas the 300 will only go 40-45 top speed but because of the tall gears can do that all day long (except on uphills)

 

If I hit the paved roads, I can cruise at 51-52 as far as it is flat. You can tell that its hitting the rev limiter cause its not winding out any more, and its not really screaming out the RPMs but it doesn't slow down. Sure the speed falls when you go up hills, but it winds right back out when things level off. Cruising at 50 on a 500 isnt a problem.