@Luffy27, great first post!

If the payouts proceed automatically every hour as long as there is sufficient balance, 10 days should be a sufficiently long time to have a decent rough estimate.  Yet, I'd trust that btcguild has a pretty good idea of each user's hash power, and their fastest user is still 566620 at 2.4PH.

I suppose the payout address could be the same for multiple users. But in that case, why not use one single payout address, instead of splitting into 2 (or more)?