I just love my Innov8 shoes. They are the best thing bar none for running downhill on wet grass, and have cushioning too for hard surfaces or roads. Mixed surfaces is what I understand cross country should be about. However, deep gloopy mud is when the spikes come into their own. I got mine cheap and second hand, ex track spikes, and just screwed a set of longer pins in.
The Innov8s may not be cheap, but they are good. Of course, they won't wear out as fast as road shoes either.