Overall a happy experience, also some S-WORKS specific details
I already had a Specialized branded mount for the faceplate of my stem that looks very similar. Major differences are that for the OEM one I had to DIY engineer a quick-detach for the Gopro flange, whereas with the Chisela it's provided by the manufacturer. The other difference is that the Specialized mount is a glossy black, which really did not match the texture of my stem or bars at all.
I used Silca's nut insert under the faceplate, instead of just re-using the OEM one, which would have allowed me to not move the bars out of position. I would do it the other way next time, the Specialized version is larger, looks a lot more solid and doesn't rotate out of position as easily. There's a trick to attaching the mount to the nut of getting the bolt started, then pulling on it to keep it in position in the slit while tightening the mount into position. Of course, looks could be deceiving and the diminutive nut supplied by Silca could be even stronger than the original.
Once attached, the mount feels very solid. I haven't loaded it down heavily, but there's a good bit of rigidity even with the spindly S-WORKS version that looks like you could just break it off if you wanted to. I am pleasantly surprised. Hope I stay pleasantly surprised once I start riding more with a light attached to the bottom.
The head of the Silca mount looks more elegant than the original, partly because it doesn't try to be compatible with so many different head units. However, since I don't plan to…