This, my friends, is what RTS gaming is all about.
There are a bunch of races who play uniquely, and there are even different sub-clans within each race you can pick. There is also an awesome "Army Paint" feature which allows you to customize your colors and banner that is displayed in a game you play online.
The game itself? RTS at its finest. Basically the game has "control points" on the map that you take over. The more points you control the more income/units you acquire. But the maps are heavily populated with these so-called "control points" so you aren't screwed if your main base gets wiped. You can spread across the map so you aren't ruined completely. The units and races are probably some of the most varied I have ever seen in an RTS game. And battles are breathtakingly beautiful to watch. I am thoroughly impressed by the different units and their graphics/animations even though I have already played the game many a time.
My recommendation; you are NOT an RTS fan if you don't own this game. You will not be disappointed.
Also, I am HIGHLY looking forward to Mark of Chaos which takes place in the classic medieval Warhammer universe. Things just keep getting better and better.