Good aliens book?

[Brutorz Bill]

Oh yeah, this is a good one: http://enworld.rpgnow.com/product_info.php?products_id=1090&it=1



Picked this up for five bucks at I-CON.

I picked this up after your recommendation. THanks! I will definately be using some stuff from it in my upcoming Star Siege Campaign.
Is the Core book for it useful as well? Core Command??