Portal Pro is a set of test chambers focusing on solving puzzles locally rather than using complex fling techniques. The goal here is that the solutions are hard to come up with but easy to actually do.
A very good and creative mod. The only thing that made me rate it 9, is the ending: very boring, you could make it better, Mevious.
And other thing: the new GLaDOS voice sucks... but the chambers... are awesomly well made, hard and beautiful.