I specifically wanted a larger telescope to do ever fainter stars. Variable star observing differs from deep space observing in many respects, the most important of which is the factor of time. Don't observe M13 tonight and no problem. It will still be visible tomorrow, and possibly a lot better. Another critical difference is I am only looking at stars.
Increased magnification decreases the sky background which translates into fainter star visibility.
With my 18 inch I usually work at 300X, even though the seeing conditions are not necessarily all that good. When seeing is above average, I will work at 428X. I use Nagler-type eyepieces which seem to perform extremely well with short focal length telescopes which is exactly what Dave Kriege of Obsession recommends. These differences make all the difference. If I look outside and it's clear, the telescope comes out on a moments notice. Seldom do I have the luxury of waiting for the scope to reach ambient temperature.