and its still better to buy S3+ than S4
while S4 temp is gonna be exactly the same as S2, above 45C in the open space without AC, while S3 below 45C
i dont think S4 is gonna be better than S3
I disagree here, simply because the S4 has something the S3 does not do easily - it plugs right in, you don't need to go through the external PSU and wire mess jungle. That is for sure worth something a little extra, probably easily another .3-.4 BTC.
For those with access to a server room of some sort, this is a very attractive unit because it fits nicely in any standard rack and looks the part.
I think it'll be around 3 BTC. If the specs are 2.2TH, then that's about 5 S3's which will run you over 3BTC when you factor in PSU costs.