Coincidentally, I received BJ's Wobble-Naught fit this past weekend.
I was still making tweaks to my self-positioning because I recently bought a new saddle, but the changes were even more drastic than I expected. My seat is now 2 cm lower and 2 cm further back than before. There was a cleat adjustment of about .5 cm towards my heel, and my bars now have an extra 1 cm of spacers under them. BIG changes.
I'm also incredibly more aero than before, even with my bars up 1 cm. I need to practice holding the straight-back position like BDC, but when I do, it's golden. It feels weird - like you're sticking your butt in the air and arching your back downwards - but when examined in the mirror, it's just straight and looks PRO. And mechanically it feels efficient for legs and lungs.
My evidence that this system works:
1) He said my previous position wasn't properly activating my gluteus muscles. The next day on a long ride, the first thing I noticed was my ass muscles getting fatigued from being awoken for the first time.
2) He said my previous arched-back position was making it harder on my neck to lift my head - hence my on- and off-bike neck stiffness. Now that I practice flattening my back, my head naturally swings upwards and my neck has a much more comfortable range of motion.
3) Just through the body measuements and computer calculations, the system found the exact place in space for my sit bones to interact with my saddle. Part of the system is factoring in the sweet spot of each individual saddle and placing it relative to a laser line that runs the seat tube angle.
4) No more numbness in my left hand - I never figured out why, but it was only my left hand and usually only while I was on the hoods. That problem is gone, as evidenced by my delightlful 2hr trainer session this morning that usually sets it off.
5) I never liked the way my balance and power felt while standing on the pedals - but didn't know to address that. The cleat adjustment has me feeling like I'm standing on solid ground and power transfer feels remarkably better out of the saddle.
6) I am no longer using a cut out saddle, but the system took my taint entirely out of the equation.
I can't say anything about power yet, as in I don't think I actually have more power than before. But the sensation since the fit is that I have easier access to my power, if that makes sense. Either going uphill, or tucking and closing a gap, everything is moving more efficiently than I've ever felt before. Watch out MABRA, here I come.
On the downside, my quads still burn when I'm pushing 400W for anything more than 1 min. I was really hoping the fit would fix that. I'm going to get my money back. ;-)