Re: AntMiner S2 1TH/s Miner (1w/GH/s) Batch 4 is open for sale
price is still to high 
+1
S1s are now about $200 a pop. For those who are math challenged, that's $1200/TH unpowered or $1560/TH stock with ATX golds.
Sorry to say but price (including costs of PS) and power consumption is not the only means of comparison for product value between S1<>S2.
When Bitmain can also make the S2 as reliable as the S1 and ship it in working order to customers with a lower sale price then I will take notice.
IMO Bitmain has done themselves a disservice by trying to build a 1TH miner with their existing ASICS.
As an EE and embedded software engineer I see these problems:
1. Bus based systems using card edge connectors - unreliable (see original IBM PC)
2. Beagle board is hobbyist grade - unreliable, known for SD card problems
3. Too many ASICS - unreliable
4. Shipping problems because of #1 above.
The S1 is rock solid because it was designed that way.
1. Two blades solidly attached to a metal frame and connected with ribbon cables.
2. Commercial quality controller in the TP-link
I assume (hope) Bitmain cobbled this together as a stop-gap while they ready their next gen ASICs.