Just my 2 cents here. the .58w/ghs power vs s4's .70w/ghs power.is not what I'd call minor.
That being said .51w/ghs of s5 is better.
Now s5 price + psu (+shipping on psu)
vs price of s4+ (on s5 and s4+ if from bitmain shipping is included)
The psu problems of s4's would be gone as 220v power would halve the amps, which puts less heat on the cord going in, and probably some other parts before turning it into 12v dc, less strain. less "loss of the magic smoke" as a friend put it (blowing a cap.. obviously it runs on magic smoke because if you let the smoke escape, it doesn't run anymore.) 
220v for the home.. damn, you either run it yourself or bounce it from the dryer, and hang your clothes on a line. hehe. Personally, I have a friggin' industrial heater in my house which after the first electric bill I won't be turning on again unless the next ice age comes on. I "could" run the lines that go to that to a breaker and split it up to run multiple s4+'s BUT as others have said, it's not exactly a deal at that price.
Currently if you UNDERvolt/clock an s4 you can cut the heat, and get better power usage.. not .58w/ghs, but hey, if you bought it cheap enough.... (I did NOT, sadly, they were still running a grand when I got mine, and went on crazy sales by the time it got here) Hehe.
My advice, like everyone else, is wait... UNLESS this thing fits your needs/capabilities. I mean it DOES comes with a 1600w psu, damn. I've been contemplating switing over to 220v, but I'd prefer a much lower price before picking up one of these, and by then they should have something akin to an s6 out.
