64 pages seems agonizing enough... after a quick glance it still seems like an excellent reference, though.

It is eminently readable... Don't let the page count scare you -- the illustrations pad it out a lot. It's much more of a tutorial than a reference.

I'm pretty excited to read about it. I learned like half a lecture on conjugate gradient stuffs, more just like, "its this optimisation thing..etc". It'll be nice to have a look through it and get a better idea as to what it is and how it works.