The math never worked for me. If I can afford, say a $5K amp… I cannot afford two. I would always match amps… coherence. There is nothing worse than mixing sound qualities (a planar guy for a few decades). So, if I could afford another $5K for amplification… I would choose a $10K amp… it is going to have better dynamics, a much lower noise floor and more natural sound. So… biamping completely loses every time for me.