Sort'a true. The thing to keep in mind is profits fall exponentially as the difficulty climbs exponentially. Power consumption becomes increasingly relevant with time, but, at the point when it begins to matter (coins mined ~= cost of electricity), being 50% more energy-efficient only buys you an extra month of mining at a ridiculously low profit (if the difficulty doubles during that month).
It is more complex than that. Lets look forward a little bit.
My guess is that by end of Q1 2014 we are probably looking at 16 Ph/s. That would be difficulty of 2.2 billion.
At this point ROI will be significantly reduced. Even if ASIC companies slash prices to the bone electricity will be making up a larger and larger portion of gross revenue. An Avalon miner at $0.10 per kWh will be spending 80% of gross revenue on electricity. All of these things will weigh into future sales. The next 16 PH/s isn't going to be "easy money" even optimistically the ROI% (using the term correctly) will be measured in % PER YEAR.
During that slow climb from difficulty 2.5 billion to difficulty 5.0 billion the more efficient devices will allow miners to keep a greater portion of the gross revenue.
For example at difficulty 5 billion, $0.10 per kWh, and current exchange rate:
Avalon & AsicMiner - negative operating revenue. would need electricity <$0.056 just to break even ($1 in electricity produces $1 in coins)
BFL (65nm) - roughly break even higher difficulty will require going idle or selling unit to someone with lower costs
KNC - power cost is 36% of gross revenue
Bitfury - power cost is 18% of gross revenue
Other 28nm players - power cost is 17% of gross revenue
Note at this point I don't think it makes sense for anyone to place any NEW order (analyzing existing orders is more complex because a lot depends on early growth, timing, etc). It is very likely every single company will be forced to cut prices 50% to 75% or more over the next three months to move units. Since new units aren't going to reach break even in the next 90 days it makes more sense to wait for the inevitable price drops.
https://bitcointalksearch.org/topic/break-even-difficulty-by-hardware-efficiency-power-cost-value-of-btc-281279The simple version. Sure if you think difficulty will grow exponentially (doubling every 2 months) until we hit 50 billion or so and everyone even a Conterra miner with no AC costs and $0.05 per kWh electricity is mining at double digit losses then sure efficiency doesn't matter. However the more realistic scenario is that as difficulty piles up and the "day 0" returns drop sales will slow. ASIC providers can cut the costs of the chips but that only means efficiency becomes even MORE important. There will be an inflection point where the growth curve flattens. The laws of physics ensure that will happen otherwise in roughly 4 years mining will use more energy than the entire human race uses for all other purposes combined.