I realize this is an older post, but I have an electric wondermill and I really like it. I've had it for years. I get the "jet engine" analogy someone said about their mill! : ) It grinds fine and course. You can grind corn, but it would be finer than grits or corn meal. I use a little tribest blender for that. It also cannot do oily grains such as
flax. I use the tribest for that as well.
I also have their manual grinder. We do not use it very often, it is a bit labor intensive.... although I know a lot of people go that route. We have it as a back-up. But, that thing grinds VERY fine flour. I was amazed the first time we used it.
I hope you found a great grinder.