Sorry, I just assumed you were from Ann Arbor. I'm not very good at using Hubski. I'm sure it says somewhere where you're from.
The Lowbrow Astronomers are a local group here with big, custom scopes that they let the public look through at open houses from time to time. They like to talk about "photon gathering" all the time. They can answer lots of questions. Just a lot of fun looking back in time through their scopes. http://markbialek.com/astronomy-at-peach-mountain/#[gallery].../
talking about "photon gathering" is pretty legitimate, so long as you're shooting RAW, you're literally counting photons. For a normal daytime exposure where there are billions hitting the sensor per second, big deal. But for astrophotography where there are so far fewer, it's a pretty big deal. Think of each photosite as a bucket. Each time a photon hits it, it fills a little more, and the recorded exposure is a little brighter for that pixel. Electronically, each photon disrupts the electric field present on the photosite, and the amount of disruption is the # of photons, and thus exposure level. So yes, photon gathering is something to think about indeed, you just have to be super nerdy. Not that there's anything wrong with that ;)