There's a lot more to it than just treadware ratings, you can only really use them for comparison between the same tyre, so the 120 NS2-R is going to wear faster (and therefore is likely to be grippier than) the 180. Most track tyres don't do well on the treadware test because they're crazy soft.
The 180 NS2-R's are good, very consistent, but I certainly wouldn't say they're as grippy as an AD08R. My Pilot Sport Cup 2's are grippier than either of them and they've got a treadware rating of two hundred and something IIRC.
All treadware tells you is how much of a tyre is used by driving 7,500 miles in Texas or some such thing, can't remember the exact details now. Honestly, I'm not kidding, google it!