I have several Win7Pro/64, 2*4 Xeon, 32GB RAM, hyperthreading, all SSD-based systems. The core software setup is identical, but each of them has specialised functionality. On each and every one of them NX-D is, like the NX2 predecessor, unbelievably slow. PN flies. So does all other software.
PN had issues with networked drives earlier that could delay its start up, and browsing these drives were quite slow. However, these problems were taken care of in the 1.3.x versions so now there is almost no difference between local and network drives provided a gigabit network is in use.