I cant say i am truly sure about this...but i dont think it increases ur speed or your aggro range.
although you maybe smaller, your normal size is still what the game uses in reference to other objects. So, mobs would see you at the normal distance no matter what.
Since you are smaller, you need to move at about double speed to cover the same distance as your normal size. Same goes for growth charm: you seem to move slower, but you really are not.
Those charms donot affect your performance while playing in anyway. Camouflage charm is the only charm that does affect your gameplay. Hope i made sense

Undead...
Alure- Druid/ Posiedon117- Mage
"Everyone has the right to be stupid,but some abuse it too much!"