In short: I do not recommend them at all.
When I was getting back into miniatures, I bought a bunch of different brushes and I thought the Army Painter ones seemed good. They have not held up, at all. I should make the point that I'm not hard on my brushes. I don't grind them against the bottom, etc. Every one of them, within the first session or two of using them, the points began hooking. And then they started fraying. I have the insane detail brush and literally, after the second time using it, it's frayed all to hell.
I will never, ever, ever buy another Army Painter brush. If you need a brush, look elsewhere.