Now, I just started this game really. I certainly don't presume to know a whole lot about the intracacies of balance in play here.
But while I was playing the game and reading through this: http://spreadsheets.google.com/pub?key=p7xc_snd9Cc-6o2UwvPEWUg&gid=6
I noticed that advent does not have a refinery, at first I thought "Well Advent probably get some other building that the other races don't." But according to the above link, that's not true. While playing I noticed that resources, metal and crystal, are at a huge premium and they are, quite often, the limiting factor on research, expansion, and fleet production.
So, I'm wondering, why do the Advent NOT have refineries? And what DO they have to balance this out?