We live in the southwest (northern AZ), current MDT is 34 feet long, new hdt will be about the same (total length). currently towing open trailer with sandrail, planned to have enclosed for two cars. new RV will be under 12 feet high ... we have a 14 feet shop door
, but we try to build it nimble for the many scenic backways. ...
...when the columbia is inside your size limitation go with it. In the Southwest you will not be very happy with the M2. The hills will kill you (up and down). Also the Columbia is build for driver comfort, the M2 is a city work truck. Columbia will cruise the speed limits even with high wind, the M2 will not keep up ... and most likely the Columbia will have better milage then the M2
We did the medium duty mistake and are currently upgrading to a Pete 379 with N14 cummins.... can't wait to have the three stage jake to go down the Laughlin grades or the mountain pass and the 1550 lbsft of torque that will make the uphill driving relaxing (and having some fun with the DP's)
Thomas