DiabloMiner is the currently the best known miner to use; poclbm and phoenix-miner both are incompatible with p2pool's mining!
Can you clarify what they are doing that is incompatible? Is it just that they don't actually verify a share against the given target? I "fixed" that by modifying my proxy to check a submitted share against the target and silently drop them when they are not valid so that p2pool never sees them.
No, it's because their long polling implementations ignore updates pushed if the
previous_block field in the getwork's block header didn't change. Shares have an internal
previous_shares field that needs to be updated; This leads to a lot of stales because the miner works on expired shares.
Where can i see how many shares are "completed" of the current block/round?
That concept doesn't really apply to p2pool since it isn't a proportional pool. It simply pays all the shares in the last day, and forgets about ones before that. I can estimate that the equivalent of about 140815 normal difficulty-1 shares have been produced by looking at the time the pool's been active and the average hashrate:
7*24*60*60*1e9/2**32 (one week at about 1GH/s).
General notice: Also, I'd urge everyone to update now as there have been a lot of interface updates and a couple memory improvements. A new py2exe Windows executable has been posted on the first post.