Wow, this is like enough info to make my leaves turn brown and fall off.
There are good things about North facing slopes (or South facing slopes for the people in New Zealand). The temperature tends to be more constant on the North slope. So, if you are on a south slope, you will go through more freeze and thaw cycles which can be hard on equipment as well as on evergreen leaves.
Speaking of which, if you look at a hill and see that one side has deciduous trees; then you can usually figure out which direction is North and which is South ... unless, of course, you are in New Zealand, in which case it is hopeless.