As a shielder, the only real problem I see is a prolonged stun in the moment of shieldbreaking, combined with a lack of "drop shield" button. For that reason, I binded "holster weapon" to the mouse, in order to drop shield slightly faster when needed. Of cource, this is not much of a problem when facing a bladed or blunt weaponry, but axes, especially wonderfast elegant poleaxes, which utterly destroy a shield in 2-3 rapid sideswings, and than finish off stunned opponent.