They were as good as Morganna The show really needs another good magical person, aside from Merlin. They say it's important to bring back magic but apart from Merlin and Gaius everyone who's used magic in the show as been evil!
On another note (as it's just occurred to me!) it was nice to have another Morganna free episode, having her show up with a new evil plan every week would have been ridiculous! Yes there was still magic but it was more about magic rather than using magic.
Also (another thing i've just thought of) shouldn't The Disir have recognised Merlin? They knew Arthur and Mordred (?) but seemed shocked at Merlin's magic. Maybe he's only known by the druids?