JP mag just did a test with AEM and a couple others.

they all showed some improvement, but only one used a smooth replacement airtube to the TB. That one gave the most increase. Per DYNO testing.

the open element reference was to others like K&N FIPKs and such. I have a K&N FIPK on my Tahoe and its awesome, but I wouldnt think of using it in any of my 4bys. Mainly due to the enviroment I live in. (when it rains) it gets wet out here, and there is always water somewhere. I saw a Volant intake for a TJ, and I saw what you are talking about with their closed replacement airbox. Nice system. I just havent looked for or seen the one for the JK yet.

 

You can get them here: http://www.4wd.com/productdetails.aspx?pid=17638

 

Volant doesn't update very often. I bought the intake and exhaust for my tahoe like 6 months before it was on their site.