Small Scale Military Headquarters

Hey everyone, I noticed some "paint pens" at hobby lobby, (in the craft section).
I was wondering if anyone has used these on any small models, like 1/144th canopy, and how affective are these pens?

Any reply would be helpful.

-Derek

I've used the Tamiya ones before on model cars. Good to use if there is a moulded edge (or raised detail) to run the pen tip against. Are they bullet tips or like a block/wedge tip?

Bullet tip, I'm just looking for an easy altunitive to fine brushes, for small detail, touch ups, ect....