I've got the 120cm pair and it worked just fine for my hexamid; just playing with a new stratospire 1 and used both an adjustable CF pair and the BD z poles. Honestly, I got a better pitch with the z poles!!
I assume it depends on the shelter...waiting on a cuben duomid and I'm curious to see how doubling up the Z poles will work as the center pole. I can certainly take the heavier alpine cork ones, but I'd prefer to be able to use the z poles.