What are you expecting to gain from the change over? I used to want them too, like the old days. But with CAD there is no real benefit worth 1500 to 3000 for the cost.
I'm sure that your response was directed to the OP, however as a guy that has had them for 8+ years I will interject my personal opinion.
You are absolutely correct that the CAD unit the factory put in place likely makes it cost prohibitive to an extent as the front driveshaft isn't actually turning anymore.
However, it eliminates wear on the front axle U-Joints when they are not engaged, and the front differential is no longer spinning either. Also the biggest thing in my mind comes from utilizing tapered bearings rather than the uni-bearing design the modern front hub assemblies have.
The kits utilize common bearings that will be easily found in most auto parts stores on the shelf should one fail, and with the ability to actually maintain the bearings actual failure is very unlikely unless neglected. Likelihood of losing a wheel with a tapered bearing design is rare in comparison to a sealed unit where there isn't always warning signs before it lets go. Another real world gain is the ability to eliminate the problematic CAD unit with a solid axle shaft on that side.
That I have not actually done yet, but would like to as vacuum problems are commonplace as these trucks get older, and a broken line somewhere suddenly means you don't have 4x4 anymore. Other option would be the posi track conversion to a manual cable that shifts the collar.
With all that being said, @bigfish95971
at 600 whatever thousand miles on your truck I would imagine keeping it mostly stock is doing it right. Problem for me is taller wider tires that will prematurely kill stock wheel bearings.