As the owner of a 2006 Chevy 2500HD 4x4, following are my thoughts.
Cons:
1) The frame rail is low as compared to other HD trucks. This means less ground clearance which you will notice on dirt roads.
2) The independent front suspension means you have to drive slower on dirt roads because the front end tends to drop into dips in the road.
3) Through 2004, Chevy had problems with their fuel injectors. Expect about 100K miles out of a set.
4) The 26 gallon fuel tank available with a 6 foot bed is too small for me.
Pros:
1) The frame rail is low, which means that both the bed height and cab height are low, which means lifting things into the bed are easier, and getting in and out of the cab are easier.
2) The independent front suspension makes for a very nice on-road ride. It handles well and is very smooth.
3) 2005 and up 6.6L Duramax's don't have a problem with fuel injectors.
4) I consider the Duramax with the option code of LBZ (available on 2006 and early 2007 models) to be the best diesel made. They worked out all the bugs from their previous 6.6L diesels before having to add things like a diesel particulate filter or urea injection.
5) The Allison transmission offers the best of an automatic and a manual. I have the 6 speed, first available with the 2006, and it is just as good at slowing the truck as it is at pushing the truck. I've decended 13% grades with little brake usage by selecting a low gear. I have read that the 5 speed Allison is just as good, but it doesn't have the extra overdrive gear that the 6 speed has, which gives me good MPG on the highway. Decending those same hills in a '99 Dodge with a regular, automatic transmission, I had to use the brakes a lot despite being in first gear.
Note that I installed a 4 inch lift and a 52 gallon fuel tank to overcome cons 1,2, and 4, but the lift more than countered pro 1.
I would agree with this (for the most part).
I had both a 2002 F350 7.3/6spd manual, bought it new. It was a crewcab/lwb, so it was the titanic when it came to turning. I sold my built Landcruiser 80 series because I wanted more comfort when camping. I picked up a 2007 2500hd Classic with the LBZ/Allison combo. I sold my Lance camper and Ford. I love the Chevy. On or offroad the chevy rides/drives sooo much better. The IFS allows me to maintain a higher speed offroad and it is just less fatiguing overall to drive.
It does sit low, but I have only found that to be a problem on limited occasions (factory skid plate is no longer straight/flat, but larger tires are on the way.
If you keep it at 69 mph, I was managing 16.5 mpg with the Hawk on my trip this weekend. I averaged just over 14mpg offroad.
I used to be against the IFS, and it does need some beefing, stronger steering parts mainly, but other than that, it is so much better to drive. And it will take a truck this size anywhere it will fit.
Jack