I own three S2's (1THs) that run right at 550-720GHs poolside if rebooted twice a week. Otherwise less. One has a hashing board that dies after 5-6 hours (all x's) until it get s hard boot.
I had hoped to bump them out of service, replacing them with S4's. After seeing the initial release price, there's no way I can gamble another round. I got taken once. It won't happen again. Sorry, Bitmain. Not even close to being worth the risk. I see how you treated me on S2's and S3 Batch 1-4. Your customer relations are as shaky as your hardware.
(Full disclosure: I have ten S1's and two S3+'s and love every one of them. The S2's are just absolute dogs and S4 pricing is a farce.)
What about holding out to see what the S2 Upgrade kit looks like?
The experience that you and many others have had with S2s is a reason why I will never buy a batch 1 product from any manufacturer. I'd rather let impatient people be the testers and I'll wait for price to come down and see how they are working for people before I buy.