your quote is wrong:
"In Bitcoin mining hardware, the factors that matter the most are the speed of hashing and the consumption of power. The CoinTerra GoldStrike1 based TerraMiner series is poised to be the leanest and most powerful Bitcoin mining line in the market"
the most important is speed to market & hashing... power usage is such a small % that if you are happy to shave 50% of power costs (tiny part of equation) and give up 75% of btc production (very large part of equation) you are terrible at math or just 'selling your book' as they say
if diff hardly grew, then yes you can show gains from less power but that is madness in this reality
I would say it is even simpler than that, speed and power usage are nothing if you can't put them into context along with the cost of purchase. How much GH/
BTC is the only formula anybody need to know to.