Bitmain, any updates on the S2 upgrade option as discussed? A lot of us have paid a high amount of BTC/GHs for these, (at least I) with the understanding we will have options to increase hashing power very soon.
Right now the S3 is their priority ... as their online advert says "The S3 is selling like hot cakes". They are making big time right now on just one product.
I'm sure they will at some time bring S2 updates out, but I wonder if you would make ROI after including the initial purchase price ... and maybe you would need to purchase a better PSU to raise an S2 to 2TH/s+ ??. The S4 (or whatever it gets called) might be interesting, but I've decided to sell my S2's and wait. Somehow it feels safer, hopefully keeping ahead of the difficulty curve.