I think there's no way around looking at past art and thinking that it's not good enough. I believe even pro artists feel like that, so it's more about learning to be proud of your work regardless of the quality, while at the same time being objective, critical and improving for present and future work.
Whenever I go back and look at Chapters 1 and 2, I get this feeling that it's pretty crappy and would like to redo it, otherwise it will put away new readers. But then where do I stop? Do I spend a month or two redoing them when I could simply create new content? Unfortunately I simply don't have enough life to do what I wish to do, so I need to do what I can feasibly do with the life and resources life has chosen to provide me.
On the flip side, I think there's value in seeing how the content improves with time. As fans, we love looking at the humble beginnings. For example, fans of one punch get a lot of fun from comparing how far the work they read has come. Not just from the author improvement, but the project as a whole.
For example, here you can see how far Saitama has come:
Keep in mind the author is probably very embarrased about how the art compares (even if it's two authors), but at the same time, he chose to be proud of it and do more content instead of replacing the original work.
We say it frequently, but we really are our most harsh critiques.
You are totally right about enjoying the journey though. I personally try to enjoy every step of the way, and always get a kick of looking back and seeing how far we've come.
Anyway, that's enough ranting xD
Maxus is coming along well! I think the mayor change is with the hair strands. I also noticed are more pronounced.