We have the wondermill junior delux. 100 rotations is about 1/3 c of flour and takes me about 2 minutes (plus extra time for dealing wit my toddler... she hangs on my legs as soon as she sees me grinding). It's not terribly quick, but if you don't use that much flour, it's not too bad. DH likes using it for some upper body exercise, so he grinds me 5 or 6 cups a couple times a week for big baking days, and I grind smaller amounts between.
We also grind flax seed with the steel burrs, and it is delicious... so much better than when we used to do it in the blender. Don't tighten it too much for the flax seed, or it will be aganozingly slow. There's a sweet spot between grinding it finely and grinding it quickly.
I tried grinding almonds on it once, and it had a really hard time feeding the almonds, even when I chopped them up.