It's not just the size that counts.
Yeah yeah. That's what all the guys say. 
Lol J/K, but you really are right. It always amazed me how KNC was a 28nm ASIC, and yet the BitFury chips are 55nm and consumed less power (per GHs). What's the advantage of a small 28nm process if a competitors 55nm chip is more efficient, and runs cooler?
(yes, I know the actual answer of how BitFury is more efficient, but I still think it's funny).