I'm in the process of getting a custom mtb frame done and have a question to anyone who has experience in having or have done internally routed shifter cables as I am toying with this idea. Besides having a cleaner look (IMHO), do they generally work well? I've seen the old Klein bikes with the inner plastic cable guides that seem to work fine from what I understand and other's with some sort of built internal cable guides. I've heard that some do not shift as well but others do. Any thoughts on this or how it should be done properly? Or not at all...Thanks in advance.