My experience with biomat is mixed. I've used them at the Hansa Center. They use them in both the massage room, and while you're on the LUX machine.
I found that I was fine with the mat while on the LUX. I felt I had good healing experiences there, but I don't know how much is due to the LUX vs. the biomat.
On the contrary, I couldn't lie on the mat in the massage room, and had to unplug it. As soon as I got on it, I felt revved up and awful, very much like my EMF sensitivity symptoms.
Have you had symptoms of EMF sensitivity? If so, you might want to borrow a biomat and test it in your own home before buying one.
There has been research indicating that far-infrared can aggravate or stimulate some infections, so depending on which infections you have, far-infrared could be contraindicated. I used the bio-mat for monthes with no benefit and some worsening of symptoms. Others though, have reported positive results, though if it was really that beneficial it would be obvious by now, as they have been around for years and used in the lyme community for a long time. Testing it sounds like good advise.