There is a bewildering array of tread patterns, sidewall construction and rubber compounds on offer from all the manufacturers. Plus the new NN is somewhat different to the older one, so it’s hard to know if you are comparing like with like on these discussions.
Personally I find that the rubber compound makes more difference than the tread pattern within reason. So, trailstar on the front and pacestar on the back tends to work for me and a trailstar NN can provide more grip than a pacestar HD if it’s not too muddy.
It’s also worth noting that the weight of a RR and a NN are pretty much the same if you compare like with like.
I like a pacestar NN on the back in the winter and a pacestar RR in the summer (both 2.25 with snakeskin sidewalls). For the front I tend to stick with a trailstar HD year round, but may consider a tralstar NN if we ever get a summer. Back last year when we actually got a decent summer I went down to a 2.1 RR on the back without the snakeskin protection, which was fun but rather puncture prone.