I think there are two key factors to consider when comparing mining systems/chips. 1) system dollars per GH. This is where big hot chips like Hashfast run into trouble. The cost (expensive board, big power supply, water cooling) makes scaling a mine too expensive. 2) system power (at the wall) per GH is also a factor as we all pay for power. The lowest I have heard HF do is about 0.90w/GH at a low hashrate 320 GH/s. There are lots of small chip systems that beat the crap out of this system power per GH. So small chips is the way to go for both cost and power.
The power numbers are wrong there. It's a Habanero as opposed to a Hashfast board, but it's running 405GH/s poolside on a 60 minute average (not what cgminer is reporting) and it's pulling 341W from the wall (including cooling) using a $40 850W HEC silver rated PSU.
I know that hashfast babyjet boards are not that efficient. I measured mine originally with the water cooling and got about 450watts.