Just a little nit.  The stats, at first glance, appear as if the blocks themselves are larger or smaller than difficulty would suggest [which happens].  One might read from the page that the blocks are larger than normal [when red/negative %], but it seems that you are indicating the number of shares submitted for the number of blocks earned won over a period of time?  In that case, it still perplexes me, as the number of shares per solution should largely be the difficulty divided by the percentage of total network hashing power that BTC Guild wields.  What am I missing?

To be fair, the same question can be asked of Deepbit too [I sort of always thought it indicated that larger blocks or smaller blocks than difficulty were been doled out for mining].

The more stats the better!   Understanding them exactly is an added plus [I have been working 14 hours straight today and my mind could be a bit addled].