I have them. They're not too bad, they do cool down the intake manifolds quite a bit, but I have no numbers to give any quantifiable differences since our IAT sensor is located in the Y-pipe before the manifolds. I did a 150+ mph run and then pulled over and touched them, they were still hot but not too hot to touch them like before.

The only issue is it does not cover all of the bolts and some people have over tightened the ones that it does not cover, and this breaks the seal. It's hard to explain without pictures... I'm going to take apart my supercharger in the next few days and ceramic coat my intercooler, so while everything's off (or while i'm taking everything off) I'll post better pictures and then explain what I mean. The picture above doesn't have the same issue ours has, or I could just show you on that one.