At first I hated PGL/MNK but now at 42 I am in love with the class. That being said...
I would like Fists of the Wind increase run speed more than it currently does. Not a lot but just a tiny bit more. I would also like to see Shoulder tackle cooldown lowered, stun either removed or changed to not effect stun immunity, and the minimum distance lowered a little.
With those changes I would be 100% happy with Mnk.