I have one on my house and I am pretty happy with it.
It's easy to keep it nice and clean, no need to paint it, and so on.
Of course you could melt it, or cut through it, or smash the small glass insert (but not pry it open, as there is a metal frame construction and sturdy hinges and a 3-point 'jimmy proof' locking system)
But which burglar would do that in our residential area?
I think that's a rather unrealistic threat.
They would rather try (and only try

) to pry open one of the windows.
Cheers,
mh