I have these hills, that I will probably not use, ever. The reason why is that they are not stable enough to have figures without washers on them, on it. I don't glue extra bases on my figures, so the hills are very hard to use for me. That doesn't mean it will be hard for you to use them. I've seen that flames of war players like them, and there is no reason why they shouldn't be able to be used as terrain in most cases.
Here are some pictures, and a figure and some trees so you can see the size. Note they are hollowed out.
I am selling them, so offer me something for them. I will accept figures as trade too. :)