I've ran the NT01's. I've also ran the RA1's.

To put it simple: The NT01's are better in everyway. They don't need shaved (but can be), they provide much better initial full-tread grip and last longer. I wouldn't hesitate to get them as a great 100 treadwear tire.
Like you said, they aren't the fastest when compared to lower treadwear tires like the Z214, V710, R6, A6, R1...