My theurgist found it nicely useful actually.
I must agree with callen
I started a thread about automata recently because I have had trouble seeing it's usefulness and thought I'd finally found something.
It derailed horribly, but that happens - perhaps because a certain can of worms got opened.
So far, for this thread I could support:
Vulgar Alchemy (I too thought every magus could do this? And why is it so hard?)
Automata (By RAW they have no Intelligence. We have no idications of how complex their orders can be, They are mostly very expensive, very limited Invested Devices as far as I can tell. This is a major virtue.)
Everything else mentioned in this thread so far has been situational (at worst) but certainly useful to the right character.