Re: [850 TH] Slush's Pool (mining.bitcoin.cz); TX FEES + VarDiff
Bear in mind that Slush does not have direct access to your miner's hash rate, but has to derive it from back-calculation based on the work performed. Your quoted variance of 15% is not something I would personally worry about.
I know they're not going to be the same, but I hadn't usually seen so much as 15% variance. Again, I'm not too worried about it, and I'll know more only after the block is solved.
And I believe you probably meant "empirical evidence". 
Quite right. Thank you very much. I'm always happy to be reminded when I get grammar/wording/spelling wrong. I need to continue to improve if I want to have the ability to correct others. ;-)