braking question

[Slamtry]

I have been told enough times by people whose intelligence I respect that
a car achieves its best braking performance NOT when the wheels are locked
up, but at some point before that. I have never understood this. It seems
to me completely counter-intuitive, but let it go. Here's my question:

Given that my stock brakes on my Classic will lock the brakes up, how is
that the NX2000 upgrade will help me? After all, if optimum braking is
achieved at just before wheel lock-up - and my current brakes will lock up
the brakes very fast indeed - surely, if I managed to just modulate my
braking a bit better, I would be able to stop just short of locking them
up and thus achieve optimal braking. So, how does the NX upgrade help (in
terms of stopping distance, I mean. I am not interested in resistance to
fade.)? Will I simply reach that notional optimal braking level a bit
sooner or what?

I am sure I am missing something here. Can anyone spell it out?

Cheers

Dan Hugh-Jones