Ah, I see where you're coming from - could be so. It would be nice if forrestv chimes in with his thoughts/ideas about the upcoming blocksize increase & what aterations are needed for p2pool to take advantage of it though.
+1

You know how the efficiency is calculated? On my public node changes efficiency (up and down) even without sending share..
Also, it is possible that some miners with high ping connect to my node and their decrease the node efficiency?
ps: sorry for my bad english...

https://github.com/p2pool/p2pool/blob/master/p2pool/web.py#L165efficiency=(1 - (stale_orphan_shares+stale_doa_shares)/shares)/(1 - global_stale_prop) if shares else None,
It will change without you submitting a share based on global pool efficiency.
If there is more than 1 miner on your node then it's really not a relevant number to you specifically. All that matters is your miners efficiency as compared with the pool as a whole.