the best one is indeed the innosilicon, the other re behind, but it's not only a matter of speed but a matter of time, it's better to have a slower speed but get the miner early to start mining with low, diff because if the diff increase your faster miners it's like my slower miner
Well, the Innosillicon certainly is the most powerful / energy efficient IN THEORY, but there are other factors. Most obviously, it's price point is someehat prohibitive... for the same pice you could (theoretically) purchase 3 D3s...
The other factor is Innosillicon's track record of under delivering on hashpower and delivery date. I believe this happened with their Scrypt A4s...
But as the wise man said, "we'll see"...