Riding: Experienced intermediate freerider - hooked and unhooked basics, boosting, and playing in little waves.
Disclosure: SHQ Boardsports team rider with access to many brands and models of harness - The Flash is the one that best fits and suits me out of many that I could choose.
After several sessions I can say that this is the comfiest harness I've ever used. The combination of shaping, support, and flexibility hits just the right balance for me.
The Flash harness is the cheapest harness in the NP range and, I believe, the only one with a neoprene lining. I mention the lining because there seems to be a sharp divide among kiters who want no movement of the harness, and kiters who want the harness to twist freely - like me.
I suspect this has a bit to do with body shape. I have a skinny waist and broad back and shoulders so harness riding up is not a concern for me. I like my harness to slip around when I'm toeside and the neoprene helps this. If you are similar, this is a great harness. If not, you'll probably be more interested in the more rigid and foam-lined harnesses in the NP range.
Also, I'm using the large spreader bar (300mm) and for my shape this seems comfier than the shorter bar.
The Aluminium spreader bar is designed so that there are no bumps or protruding bits - just smooth, even curves, so there's nothing to stick into your ribs as the bar gets pulled upwards when boosting etc. The pad is firm too - further spreading the load.
Durability should be excellent. I say this because NP is the parent company of and has the same factories as Cabrinha, and my Cabrinha harness saw 4 years of very solid service. The old spreader bar broke at the welds after a year, but the harness itself, though faded, still has all stitching intact and refuses to die after being paired with another spreader bar. The Flash is very well finished and the only thing I'd add construction-wise is perhaps a bit more beef to the leash anchors, but unless you're regularly passing and dropping the bar this shouldn't even be the slightest issue.
I've rigged it so my leash runs forward on the side from the anchor point, passing under the neoprene cover for the strap buckles, so the release is near the end of the spreader bar, where I can always reach it.
All NP harnesses come with a good-looking line knife to complete the package.
As always, be sure to try a harness on before even thinking about buying it and hook into the rope on the wall that every good shop should have to check that it fits you. Try several harnesses, twist around a bit under load, and do what you can to simulate actual kiting loads and movements. One kiter's lounge chair is another's iron maiden - but for me, the NP Flash is the comfiest yet.