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I think focus is the most important thing when you image and the most overlooked. It depends on your scope and how big your CFZ is.
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I agree there, I keep being tempted by a new 8" RASA to do my stuff at F2, images are finally turning up on Astrobin to get some sort of handle on what they are like, but many of them look out of focus to me. A combination of not quite getting it right on a scope with a very small CFZ and/or leaving it alone for extended periods.
My ED72 is a lot more forgiving, but the C925 would be wasting subs after half an hour if it was reasonably early in the night. That said, before I got it a focus motor I did see telltales that even the ED72 shifted somewhat over time as it cooled down in the evening.
I automated focus for both my scopes as I am aiming to automate as much as I can. I believe the less times you physically touch the scope or mount in the night the better. Cost, among other things means that is not an option for a lot of people but I can manage it so automated I go. If you can afford it, IMO you will never look back once you set it up!