The new Antminer S7 Plus is much more efficient.
There's not a S7+ version, am i misunderstanding?
And now the latest batches of S7's have the same efficiency as the Avalon6, so not the only reason to stick with S7 is the GH/$, since the Avalon6 has a much better build quality.
The avalon 6 comes at 3.5th/s (thats hoping you have a warm room since they run lower in the cold) and the S7 is 4.8th/s. You can get the S7 plus shipping below $1100 currently. You can ONLY get the Avalon for $1112 in the current group buy and living in the US.
The better deal is the S7. People assumed the Avalon 6 would be able to flex by changing the volts but has not been the case at all.
You can order an S7 Batch 9 with shipping and import fees that will likely cost about $1150 and it isn't shipping for several weeks. A better comparison would be the Batch 8 which will run you close to $1300 shipped with import fees and ships now.
As for overclocking the Avalon. I get 3.8-4 Th at 12.2-12.4 volts all day long.
Not to mention the USA warranty - I had 1 Avalon6 replaced and it was as simple as calling them and sending it to California. Try that with Bitmain. I would also bet that the Batch 8 and 9 S7 have a much higher failure rate than the Avalon6.
Not to mention I get the Avalon6 in 2-3 days while people wait on an S7 for weeks. I make up the difference by the time yours arrives.
USA there is no import fees which reduces the cost. Also long term, 1 th/s more per miner will out perform avalon 6 even getting them 2 weeks earlier.