Hi everyone,
I thought I should add something here...
My boot is completely locked. I have the stiffest tongue, a stiff liner, a custom made suspension thing with no suspension at all, and screws on both sides that go through the upper and lower cuff. The boot is locked in my preferred angle, a lot of forward lean on the back foot and a little less lean on the front.
On my search for the fastest equipment and setup I found that a radical stiff boot makes me faster. That's the only reason and the only thing I care.
Obviously I would never advice anyone else to do the same! As you might know I have my own snowboard camp (www.carvingcamp.ch) where I coach freecarving riders. In this camp I tell everyone to use a boot with some ankle flex. You'll have a lot more control and you need less effort to make a carve, just to mention a few benefits.
Okay, so far my input. If you have any questions - let me know