I installed the full system with air box a week ago. I love it. It also took me about 4 hours to install, but I've heard of others doing it in about 1.5 hours. I took my time to make sure I did everything right. It doesn't require a new tune, and there is no mention of using any kind of insulation under the air box. The air box simply replaces the stock plastic radiator shield.
I haven't noticed any issues with the hood due to any additional pressure being directed up at the hood. I really don't think it is pushing that much air to cause any concern.
You do have to move the radiator overflow tank to the location of the stock airbox. This was actually very easy with the supplies in the package. Lengthening the mass airflow wiring was also very easy with the supplied kit.
The system looks wonderful installed. Looks like it comes stock. Now, I'm looking forward to getting a Saleen SC installed, and see if it works with the ram air system. It looks like it will, since the Saleen SC works with the stock intake box.
I would highly recommend this product for anyone who is considering it already.
Good luck.