Omni-Heat reflective?

Yep, both products follow the same basic concept of reflecting radiant heat back to the skin surface. I used to own a Fugu, and wow, that baby was warm!

I currently own one. Bought it for my spouse for when we go out in colder weather together (the Stars occasionally align the right way and allow this to happen), but i also use it when those glorious polar vortexes decide to tornado some of that Arctic air down in the SE and i go Hans Solo.

Anyways, yes it's pretty dang warm, especially with a windjacket over it.

I have a hard time reconciling the Fugu and the radiant warmth part, with the research or posts of people like Nisley, Adams, etc that say that you need at least an inch between you the heat source and the IR reflective material to get optimum heat reflection going on. Then some say that you also need a clear air gap also behind the IR reflective material.

There are some air gaps here and there in the Fugu depending on sizing in relation to your size, but in most cases not nearly an inch. I guess some still will happen–apparently just enough to notice?

Our engineers did some testing on a reflective fabric a few months ago and found that an air gap (between the reflective layer and skin) was indeed necessary, but separations of as little as a quarter-inch were effective. Then we got swamped with other projects and the reflective fabric testing had to be put on hold.

I have an Omni-Heat zip-T, and I don't care that much for it because it makes me feel COLD! Is that just me, or does it not live up to marketing spin?

I think that 1/2 inch air gap would give twice the temperature difference of a 1/4 inch. And 1 inch air gap would give 3 times the temp difference of a 1/4 inch. Bigger air gap may actually be worse. Approximately.

Possibly. It seems the tech only works for jackets and not for baselayers which I can see. I have owned two different Fugus but neither the XXL or XLT fit so they got sold off. I think I could deal with an extra few ounces for an 800 fill jacket using this tech when they go on sale for $90.