In reply to beardy mike:
I have the quark trig rest on them (with the index hook removed) but any of them should work as Petzl's shafts are all about the same diameter/shape, which is very slightly larger than the one on the NM's. A little bit of tape, or some people use bike inner tube, is enough to match the diameter and get a secure fit.
I also ground down a little of the inside plastic to place the rest over the little nipple in the axes as it seemed a better position, but other people place it just above with the nipple doing a bottom stop sort of thing.
Haven't tried the standard ones. I only got these because they were stupidly cheap, and i ordered them half expecting an email saying "sorry, there was a mistake with the pricing". Guess ideally you need a shop stocking both and swing them side by side see if you feel any difference in the swing or weight balance. Any apparent weight saving off a few grams will probably be offset by the ice/snow compacting and sticking to the grooves in the shaft anyway,
Probably be people comparing them both in the internet somewhere if you do a search
Post edited at 13:48