Personally, I don't really find the attributes to be that effective. Go compare the numbers: I'm currently at lvl 28, and I have ignored Belief and Vitality. If you look at the % of total granted by attribute, it's only a few %.
If you only want to do one thing, fine. Max out that attribute. But half the fun of playing MxO is that you can be EVERYTHING. It's only in the other games that you're limited to 1/2 Classes.
My 2$i.