If you liked part three better than this one, part four, then you can see the potential dilemma of any artist in knowing when a painting is done - and the sometimes feeling of, "Oh no! I might have overworked it."
I experienced this several times in the process of working on this one, and yet, a few days after I had the panic, I felt more reconciled to the new version. Some earlier versions I quite like, and if I could go back, I might keep one particular effect, and not keep some other effect.
In the end, it's like the forks in the road of life - you have to choose one, and even if you go back and try the other, it's never like going back in time and taking it from there. You're always in the now!