For me, like Brad, it's knowing that you didn't do it. When I'm finished working on a build I have to know that it's the very best I can do at the time.
I feel like that's the whole point of doing this. To replicate to the best of your ability. I have done a few builds since I started and a few of them I am going to do again because I am sure I will be able to improve them as my skills develop.
Anyway, that's my way of thinking but the main thing is to enjoy which ever version you want to build. What others think really doesn't come into it. Just do it your way and be happy with it. Pantherman