I like the mini map in general. However, there are two things that I would like to see different:
It would be nice if the grade indicator would change from an uphill (with a number) when the road goes up to a downhill (with a number) when the road goes down. Right now it looks like an uphill in both cases with just a tiny minus sign on downhills. It is really hard for me to see the tiny minus sign on the screen in the current scheme. This mostly affects the smaller grades since a steep up or down is easy to tell from the big picture.
It would be nice to be able to zoom out the mini map to see where you are on your route. To get an idea if you are half way done, mostly done or whatever. Now I have to remember the total distance and try to gauge it that way.