Please read carefully what I have wrote:
your net income should increase by at least 20%
This reffers to the actual avarege reported hashrate on your pool side, not just the speed you see in the miner.
Feel free to test and report back after 24hr how our miner compares against other miners, we are sure you going to be pleased.
Best Regards,
zFastminer team.
Instead of writing a dozen posts with vague statements you just could say what the miner fee is.
People wanna know that and if you avoid to answer this, people won't trust you.