I have done quite a bit of testing with all my pedals and a Radial true-bypass switcher. The Boss pedals do have rather significant tone-suck, IME. So much that I won't run them in my chain, only on a bypass loop. The buffered bypass in my VT Bass is definitely superb, as are the buffered bypasses in my Peterson pedal tuner and TC Electronic Flashback - both of which can run in true-bypass, as well. I haven't run an FFT on the Boss pedals, but their affect on the tone in bypass is noticeable through my Bergantino HS410; the bottom drops out and the bass gets thin and tiny sounding (comparatively). I have my board arranged in a way to take advantage of the good buffers, keep the bad ones out of the circuit as much as possible, and keep my signal path as short and clean as possible when I don't need certain things.