I've spent quite a bit of seat time with my set of NS-20T and I like them. For whomever researches these down the road, these are my findings:
They needed an L-pad installed for the tweeter (cheap from Parts-Express). Once I did this and was able to dial in the tweeter level, they are incredible speakers for smaller to medium sized rooms.
Very, very good imaging, sweet treble. Slightly forward mids. Fast, dry, dynamic mid-bass. Not much low bass to speak of. Although they are 8" woofers, keep in mind they are sealed and from an era in which small speakers didn't make a ton of bass like modern speakers do.
I did recap mine with high quality film caps for a few bucks. The crossovers are 2nd order hi and low pass, with air core inductors, so no skimping here.
I enjoy my set of NS-20T and will keep it in the rotation, they're lovely speakers once an l-pad is installed (all the bigger siblings in the x0T and x5T line came with l-pads for the tweets).
HTH