I've been researching some WHM's lately, and am not entirely happy. What I see is a bunch of front-ends to have such a critical role in the system, that modifying any part of the system could potentially ruin the WHM setup. What I want is a nice, clean WHM where I can control the software. I want to be able to use my own special Apache install, qmail, mysql, I want to be able to do my own compiles, etc etc.
Sure, there's Webmin, but that's not really a WHM. That's more of a server manager. But I want a WHM with that kind of capability. I basically want a frontend to my pre-existing server, which I will build.