You're asking good questions, and people more knowledgeable than me are going to, and have answered the technical questions.
Ever bought a really good pair of boots? I mean *really* good? Remember how you felt when you wore them?
I remember the first time I ever had a really great pair of semi custom shoes. I have narrow feet and needed a pair of dress shoes for my job with AT&T. It was years ago, I was a sales guy and was, (gulp) an 80 dollar shoe buyer. I looked at the shoes and saw some that were unbeliveable. they were 200 dollars.
When the shoe salesman came to fit me, I told him I was an 80 dollar shoe buyer. He measured my feet, and came back with several pairs of shoes. I tried them and they felt like, well, shoes. Then he opened up a box and took out the 200 dollar ones. I protested, he insisted, and I put them on. Damn. It was all over. I walked out with them. I felt so damn good in those shoes that my confidence and sales went through the roof. And they lasted about 8 years -- far longer than the cheaper shoes would have. So long in fact, that they ended up being less expensive than three or four pairs of the cheaper ones.
I bought a Kimber for my first and so far only 1911. It just *felt* better than the other less expensive guns I tried. So much better that I ended up buying it, and haven't regretted my decision for one moment.
Having never held a Les Baer, Wilson, Valtro, or any of the other truly custom or semi custom guns, I am convinced that there is a real *something* about them, they're probably worth the money, they probably make you feel pretty damn good, and I hope to own one someday.
Good luck in your search.
jzz