I've used NM for several projects:
So now I can conclude that the yarn holds up perfectly whether it is used for cables or texture only. It requires some serious steam blocking at first. Then NM's memory will do all the work.
Regarding the itchiness, I guess, it depends on the individual sensitivity. To be on the safe side, I would say that cardigans/sweaters would be just fine, even hats are ok, but cowls - wouldn't risk it.
Durability of NM is really great.
The red cardigan from Phildar has been washed countless times for the past two years and still looks like new - no pilling (even underarms!) whatsoever.
The best part, of course, is that with the right gauge you get garment that no one would think of asking if it is handmade (unless those people know about your addiction:). For example, I wore Stowe for a couple of times and already have been asked where I bought it.