Right now there's no real benefits of being an atrox, except being able to use a beam and da taunter (and looking really stupid in a thong =).
I don't have the numbers, but I'm pretty sure the difference in HP between atrox and sol is no more than 50-100 with maxed abilities, and the difference in nanopool is more like 1K.
Atroxes should have more HP than other breeds at the cost of less nanopool.
FIX DA ATROX FC!