Thanks for the responses. It's not that I won't be happy with the Kappa, I'm sure I will be. Its just that I really like the building process and want to keep building stuff.
My question was more along the lines of "will it work". I just wanted to know what the schools of thought were on mixed subs. I'm still going to build it and see how it works, if I don't like it I will sell one, or apply it else where.
What are the plans for the ported Axis 15? That sounds really interesting.
Is that a black stain over wood grain or a veneer?