I have mixed feelings about CNS. The leather straps I bought from them were...well, rubbish. One of them I wore maybe 20 times, and it came apart, another I couldn't even squeeze onto any watch, because there's too much material between the spring bar and the case. On top of that, the spring bar's slanted in it - the whole damn thing's been sewn in askew. Two rubber "tropics," both are uber-stiff, had to dip them in hot water to bend them to shape, else it was like putting my wrist in a vise. Marine Nationale by them - it's not even a Marine Nationale strap, the design's all wrong and the buckle hook rubs against the wrist with a sharp edge. Jeebus. The whole loop/hook assembly is supposed to be isolated from the wrist by the nylon, and that's not the case in their "MN."
So, the leather ones I bought from them were subpar, the tropics are...well...let me put it this way, if I wanted DIY stuff, I'd go buy some from Ikea.
On a redeeming note, though, I have two NATO straps by them, a Deluxe "The Black bay," and a discontinued "seatbelt" NATO in vintage Gulf Racing livery. Both are really great. So, I can't recommend their leather straps, but I do recommend their NATOs.