While I use Fostex drivers in one of my designs, in general I agree with Jim's comments here.I get around the limitations he mentions in the FE206E by using a notch filter to smooth out the treble emphasis and by rolling off the bass below 120 Hz or so. I use a separate woofer section for the bottom end. Still, I wouldn't mind having a bit more x-max available from the Fostex. That being said, I do like their efficiency and liveliness.
Sounds like the Jordans are very refined drivers. Maybe one of these days I'll have to try a pair.
Duke