I wasn't impressed with my nightcap initially, but it has proven to be useful. Why there isn't a baseball cap with a mount plate on the back I don't know.. I still pack a bump helmet if I'm going to use NVGs for any extended period (hog hunting, for example). The NC will pack down very small and fits nicely in the USGI PVS-14 carry bag.
Since you asked for alternatives:
Opscore has one for $270: http://www.ops-core.com/skull-mounting-system/
As MW mentioned, FS has one for $350: http://www.first-spear.com/pro....php?productid=17936
Norotos for $385: https://tnvc.com/shop/norotos-...-nvg-mount-assembly/
Wilcox for $460: http://www.wilcoxind.com/Skull...k-Head-Mount-P8.aspx
This vintage eyesore at $30 (search around): http://www.specwargear.com/pro...unt-flip-up-version/