The FS1 are definitely made by Futuresonics for Xtrememac. I had those for a little bit. I tried them at Macworld last year and actually liked them. Then I compared them to Ultimate Ears and it wasn't even close.
I almost opted for the Futuresonics brand, it was only about $100 but I can't see them on the site anymore. It was the EM3. The only disadvantage is that the ear piece is actually like earplug foam. That has a finite life so you'd replace them often. However, the foam is way more comfortable since it's form fitting.
