Not sure if this is in the right area but I'm looking at getting a tow rig for my Jeep so I can build it from a mix use Jeep to a trail machine. Anyways what are the differences between the 2500HD dmax & the 3500HD dmax srw? Is it all suspension? Is it worth the extra $$$ if I'm only towing a few times a month? Im looking at the 2011's by the way.