Each gun I ever built was the best gun I ever built. I put everything I had into it, and when done, it was the apple of my eye. I am sure my first longrifle was just as nice as this guy's rifle, and if I knew enough to put leave lock panels on the gun, they would have been plenty big.
When someone asks 'how can I do this better?', you know they are ready to listen. Otherwise, keep your mouth shut, and your judgement to your self.
Criticism is hard to accept; so many people, self included, can be touchy about comments on their work. When I post something, I either want to know how to do it better, or to show off. But putting your work out there means that you run the risk of hearing something you don't like to hear. If you don't take that risk, you don't grow. Criticism is a vital part of growth, I have come to realize over the years. Sometimes it is painful to hear, after putting in so many hours of painstaking work, that your fore end is too square, or too much wood is on the whole gun, etc. If I can hear this criticism, I can use it to avoid making the same mistake over and over.