Dear Sam,
Nice to meet you and your partner at NEAF. Coincidence my colleague was from the same city as you. :)
I purchased a 178MC (my older 120MC is not Mac compatible) from Highpoint Scientific again. They assured me, as you did, that it will work with a Mac being USB 3. The issue was drivers they said. However, their are notes on oaCapture's site that there is a layer problem using El Capitan. This was what I was explaining and not sure they knew. Before I use the camera, I want to be sure it works with El Capitan because i cannot upgrade my OS at this time and I would like to be able to return it in an unopened condition. Please advise if the camera and oaCapture will work with El Capitan. Thank you, Mike http://www.openastroproject.org/2015/11/oacapture-on-el-capitan/