I really liked the "yoga" comparison. Unless you start a very specific project (such as measuring variable stars, hunting for asteroids, measuring the light curves of exoplanets...) astrophotography is indeed somewhat pointless, and I love it that way. The pleasure is in the process as much as it is in the final result. Take it any other way and you'll be disappointed.
Anyone going into this for "results" will be sorely disappointed. There's a channel on youtube where talented pro photographers take cheap trash camera and try to take good pictures. I am a bit ashamed to say that in 99% of the cases, they take better shots with a $99 camera than I do with a $5000 one. But there is no such thing in astrophotography: better skies, more aperture and bigger CCDs always win.
The current most "rational" option if one wants "results" and one doesn't live in an ideal place is to rent time on pre-configured telescopes (for example
http://www.itelescope.net/) - but where's the process? Or more correctly, that's a different type of process, more "excel" than "yoga".
Thank you for that very nice article Michael!
Ah, and one word about the stacking vs single shot issue: ideally, longer shots deliver more bang for the buck than the equivalent stacked exposure. However, in practice, it depends on many factors. The most important one for casual amateurs is the background brightness of the sky where one lives. The goal of each exposure is to maximize signal to noise ratio. If you live in a very dark sky area your sky brightness might be at magnitude 24 and you'll need to expose for a long time (depending on your aperture) to reach it. If you live in a suburban area with a sky brightness of mag 19, you'll hit the limit very quickly. Any exposure beyond that limit will drown weak signals in a sea of noise and drastically lower your dynamic range. Where I live, Belgium, one of the most light polluted zones of the world, I hit the limit after about 90 seconds. Above that, I start losing signal. And if I exposed for five unfiltered minutes, I would just get an uneven brownish/yellow image.