I currently have the V-Stream 22" windshield on my NC700X. It has its own welded, tubular bracket that offers great support to the windshield and as far as I can tell, it totally eliminates windshield shake at speed. The bracket bolts to the Honda windshield mount using four 8 mm bolts with flange nuts - a solid, metal-to-metal connection. The rubber sleeve, Honda-provided "well nuts" are removed and not used at all. Installation is straightforward and everything fit as designed with rubber mounts to isolate the windshield from shock. The still air pocket around my helmet is OK but somewhat compromised by air coming around the lower sides, over the turn signals, etc. The front of the NC is aerodynamically "dirty."
There are many riders on this website that swear by the Madstad windshield.