I'm not sure where either of the above 2 CAI units are pulling fresh air from, but if it is only from the engine bay (not from outside of the engine bay), then it is not really pulling in 'cold' air. If either of these CAI units are pulling fresh air from a hole through the engine bay wall, such as through the wheel well, then is is pulling in 'cold' air.
Basically cold air intakes and performance air filters make minimal HP increase and give the illusion of more HP simply because they make more noise over factory setups and people tend to justify their purchase by embellishing the performance and fuel economy.
I installed the K&N intake and here are my takeaways and replies to your comments.
This unit does pull fresh air (through a duct), so it is a true CAI. I had a "CAI" on my 4Runner which pulled from the engine bay and know that wasn't a true CAI. So, going into this, I knew this would be more true than my previous 4runner experience.
I agree the performance increase from one of these is minimal. Was I looking to make my Yukon track worthy and smoke rubber to annoy people? No. But the joy I get from hearing my engine when I get on it is huge. This makes the 6.2 sound as it should without an annoying, constant exhaust drone.
Installation was very straightforward and easy as long as you have some basic automotive knowledge. Like I said above, the sound is worth the cash for me.
Have had a CAI on all my cars list in signature. I will say the most effective one was for my last M5....it was NIGHT and DAY difference when the turbos spooled up. These filters sat in the front grill area. Really need to look to see if there is any means to do a similar setup on the Yukon. Since my Cosra exhaust is set to ship out on Jan 6th, will be ordering there CAI as well...matchy matchy I suppose.