The Kumho Ecsta SPT is a "budget performance tire", similar in performance to the best tires in this market segment, such as the Yokohama ES100, Dunlop Direzza DZ101, Avon Tech M500, and Bridgestone Potenza RE750. These tires are designed for folks who are willing to sacrifice some performance for a low purchase price; they generally offer dry traction and handling that is pretty good (but by no means in the same class as the better top-of-the-line tires), excellent wet traction and handling, and reasonably long treadlife, all at a bargain price. I've ridden on the SPT on the track in the rain and it has awesome grip on wet pavement.
I think the SPT is a great choice for many folks for daily driving in family and sporty cars. I think most NSX owners would prefer to choose from the best tires on the market (like the OEM tires, Goodyear F1 GS-D3, Falken Azenis RT-615, etc), so that they can enjoy all the performance of our cars, rather than degrading that performance just to save a few bucks on tires. But hey, that's why they make a lot of different tires, so that each of us can choose whatever tires we want, and accept whatever compromises come with them.