Nice looking 43. 500 acres , yeah a 63 would be better. Depends on how much time you want to spend in the seat. Fuel consumption would be far less. A thought would be buy the 43 , if you have a number of big trees , have a 6 come in and knock them over and take it from there. That 43 will take out a good sized tree , if its that straight and you could get it for around 20 or 22 , I'd jump on it. Or you could clear what your comfortable with and rent a 6 for a weekend for the really large stuff. How big of a tree are you talking ? The 43 would take out a 30" tree at the base, just takes a bit.