My CAD has been locked in with a bolt since fall of 2014 and it hasn't given me a hint of trouble. As stated above you do have to pay attention to the condition of the ujoints in the front driveshaft since it's always turning. I've put about 40k miles on the truck since then and probably close to 100 4x4 boosted launches.
I've heard a few bad things about the posi lock cables and it's just one more thing to worry about. I like the simplicity of having 4wd the instant I pull the lever. A one piece front shaft conversion has crossed my mind but I'm not gonna fix what isn't broken.
I think you'll be fine with just a one piece shaft or just locking the collar with a bolt, I wouldn't over think it.