I've been wearing these shirts for many years and they're fine. However, there's been a visual change that I don't like: the old ones had a 'matte' appearance that changed at some point and the new ones are shiny. The material feels pretty much the same to me, I just don't like the looks of them now. Most shirts of this type are shiny now, so perhaps NB felt they should go along, but to me it removes any reason to buy NB rather than something else.

Also, they have changed the sizing. I wear an XL in most running shirts and they are generally loose on me (I wear a L in regular shirts) but to get an equivalent in the new NB shirts, I buy a 2XL.