Just to finish this off, sorta ...
Drove down and took a test drive in the 2013 X-Cab 4x4 2500HD ... with the Z-71 package. It's a bit taller, a bit rougher ride, and a bit rougher in steering. It's the off-road suspension package ... and I thought it might be better with the Truck Camper - but not so ...
A little too rough on the highway -- plus, the accelerator did exhibit the 'throttle lag' ... so, just for comparison, we drove the Double Cab with the standard suspension... NO throttle lag, first one we drove without that in the last two weeks. Also, smooth as ice cream on the highway - a significant difference between others we drove, including a Crew Cab ...
The savings on the 2013 was significant - but the difference in ride and options not worth it in our minds. So, we suddenly found ourselves owning a 2015 Chevy 2500HD 4x4 Double Cab - delivered Tuesday to our door.
The financial difference was about $6000 or so, but the ride difference was priceless (OH NO, did I really say that?) -- and of course the upgrades options added value as well, so not a direct comparison. The 2013 was bare/bones LT, the 2015 is LT but also has leather seats and the interior convenience package, back-up camera, and the electronic package, ten-way power seat. Would not have ordered leather, but it's there, so it's there, know what I mean ...
A lot flatter wallet, but two bigger smiles ...