So, let me get this straight..

Generally the biggest difference I find there are there is alot of high value nodes like +attack speed, + Projectile damage, etc close to some of the class nodes, that would be hard for another class to access them all without going around since the class node it self is a great way to go off in 3 directions to high quality nodes.

So in short generally best class for a specific build would be one that accents the shortest distance to completing a build and has the best access to nearby nodes without having to be 100% connected to the rest of the build.

I.E grabbing the 10% Elemental Damage 4 points off of Templar Node which would be harder to grab in the other direction and more wasteful.