I critique myself all the time, and often make changes. Sometimes they are intentional changes, and may or may not improve things. Other times they are unintentional changes and work out good as well.
There are 4 or 5 folks that I can ask for an honest evaluation, and get one..... but for the most part I accept the fact than by habit, people are just polite. They always will say positive things. And although I like to hear good things, I just don't take them to the bank.