From what I am reading, it's not saying 10% it's saying 2% to 2.5% +/- 10% so it can be as low as 1.8% or as high as 2.75% and although I don't think many people would care about it being 10% less there are a lot of people who would complain about 10% more.

And with a tiny bit of network knowledge and equipment it's easy to see where where data is flowing to and from for your miner. And see where and what is being done. MANY people dislike aftermarket mining software and would love to stand up and scream and show proof of what it's doing. A bit of wireshark and you can see every packet coming in and out of your miner. Now that's not to say they could not be doing other things in the background. i.e. underclock and undervolt when mining for you and overclock and overvolt when mining for them, but in reality that much extra programing and work for what would in the end be not that much more hash is probably not worth it.

-Dave