I don't know any accomplished artist who is completely and unequivocally happy with their work with exception of some "music" "talents" with humongous ego (and bank account). I think there are always thing that could be improved in any works of art. I think that's one of the drive that makes artists excell to the new height.
Obviously, with all the "faults" included in your work, the paying customer appreciates your skillful result and the product. I think it's a high form of compliment. I think, as long as you did the best you could in given circumstances and limitations, there is nothing to be ashamed of that the work isn't "picture perfect."