This actually from something I read elsewhere, when buying a cooler, it is better to get one that is one size bigger. For example 15" is supported on NC1000 however you are better off with the NC2000 as the NC1000 'true wind-flow area' will not be able to cover the whole body of the laptop.

If you checked, for most coolers the mesh is about 1-2cm from the edge of the cooler and that means only the inner part is covered. It is okay if the laptop is smaller than the cooler itself however in the case of 15" on NC1000, it either will fit just right or go off the edge making less area covered by the wind-flow, which in return, less cooling efficiency. On the NC2000 however, it fits nicely in mesh area.