NSP boards suck! Sure, they are cheap and bombproof, but the riding qualities are terrible! They are heavy, and like the other guy said, they are SLOW.. I used to ride one and thought it was ok, until I rode a surftech board about the same size. The surftech board is half the weight, and has a livelier ride to it, but is still pretty strong. They are more expensive, but if you want a serious board for the surf, it is worth paying the extra coin IMHO....
I have never tried NSP so I can not comment their pros & cons, but I googled quickly to find out you can get a brand new NSP short board for 300 to 350 EUR.
That's the price I paid two months ago for a 2009 north kontact 6.1 in pretty good shape. That's also the price I would be able to resell it now or in six months ... when your NSP would be worth what ? 150 EUR maybe ?
Like IHateKooks I think you should use a dedicated board, but it is not necessarily expensive !