You're asking a forum of creators, we're only a small percentage of the audience and our answers are all gonna be skewed! We tend to (not always, but often) appreciate art that's treated like, well, fine art, with a lot of time spent on it. I keep thinking of my mom, who was very enthusiastic about the webcomics she read, and was always frustrated by comics that took extra time or missed updates to finish a ~beautiful perfect page~ because "I just want to see more of the story!"
@zetina took the words right out of my mouth about writing, and I think even in art alone, there's a BIG difference between "I'm being a lot more loose but I'm still pleased with how it looks (and I want to be able to finish this story before I'm 50)" versus "ehhhh I can let the quality slip because nobody really cares about it." Gigi D.G., an artist I have a lot of respect for, has talked about being a LOT more loose with her pages lately because she wants to be able to finish them more quickly... but they're still thoughtful and beautiful.
I think "thoughtfulness" might be an important factor. We think of that as an inherent part of quality, and the first thing to go when something is rushed, but if you can speed up your process without losing your thoughtfulness, I think that can still be really great work!