I saw the seminar put on at the bow rack up in Oregon from one of the inventors of the HECS stuff and I must say it was pretty convincing there was a lot of scientific information as well as some convincing video shown. There were also some guys in the crowd afterward that I know personally that said they had used this stuff and saw a difference. The guy also said hecs was being used in wet suits with sharks, and also with dogs. I have to admit it was extremely convincing, and he really did seem to know what he was talking about. He was also very busy after the seminar and it looked like I was not the only one who was thinking a little differently about this.
I am just really skeptical of this kind of stuff and like some of the others here I just was not aware of any findings about deer having the ability to sense electromagnetic fields. I was playing around on the net afterward and thought I would see what google had to say about this I was pretty surprised by what I found. Here is one thing i found http://en.wikipedia.org/wiki/Magnetoception. it looks like there is a lot of information on the ability of mammals to sense magnetic fields. If you are interested google Julia Neef she is a researcher from Europe somewhere that has some interesting reading if you are interested in this subject especially when they talk about the possible mechanisms mammals have. Kind of opened my mind up a fair bit more.
I think I might have a hecs suit come fall.