A few notes for those going down this path (I'm doing the same).
1. This doesn't work on OSX yet. Works really well in windows though.
2. There's no microphone. I'm looking for a directional mic setup for the rpi but haven't found anything I'm satisfied with yet.
3. The 6mm lens is total crap. The 16mm lens is decent but the zoom makes it difficult to use as a webcam. I'm still looking for a good rectilinear lens in the 4mm to 8mm range that has minimal distortion and doesn't cost an arm and a leg (after all, the whole point of this is to do it on the cheap). There's no obvious candidate yet.
4. Commonlands has a couple M12 lenses that look promising. I'd prefer a C mount but you have to go with what's available. I'm going to pull the trigger on one of them to test out when I get back from vacation.
5. Arducam has a bunch of lenses, but I find them to be very strange. Maybe it's a language barrier issue, but the videos and the marketing copy are all very odd and don't quite tell you what you want to know. It feels like a Chinese company masquerading as an English company. It's all weird enough that I'm not ready to pull the trigger and purchase one of their lenses.
6. Focusing is a pain in the ass with all these lenses. You will not have the same experience as a typical webcam but once you have the focus dialed in things look great. Just don't move.
7. The HQ camera is very capable but it's limited by the bandwidth limitations of the pi interface. 1080p 30fps is the max you'll get. Don't expect 4k video.