well it was quite an expense actually, but I bought the EX495 with (2) WD2TB Green drives and over the weekend they had these drives for $139 at newegg, (dunno if its still available), so it's maxed out > 4 2TB drives.
it's just a little eye sore to see one drive critically red and the 2 brand new drives unsused, plus I need to populate them so i can make sure the rives are healthy, i can't very well RMA them after a certain time if in fact they're faulty.