We need more people like you to jump in for the long haul with their hash.
Here's a silly question. What the best Difficulty to set the s7 to?
Difficulty is set by the stratum server to make sure your miner reports ever 8 seconds with a 30% max variance window. If averages less that 8 seconds it will increase the diff, if more it will lower it. In the end, difficulty has no effect on the "best share" just how quick the miner reports a cluster of shares.