Nearly 16 hours to find a share.
When I first started mining on p2pool, the share difficulty was barely in the hundred thousands. Now I've seen it upwards of 15 million. If you can handle the variance, then you'll be happy on p2pool. If that kind of variance is too much for you, then p2pool is not for you.
True ... I found mining on p2pool not much better than solo mining ......
P2Pool is kind of a double-edged sword. If the pool's total hash rate is low, then the share difficulty remains relatively low. However, you get hit with much longer times to block. Increase the pool's total hash rate, and finding a share takes much more time, but the time to block goes down. You get the worst of both worlds with the variance. But it isn't only a negative thing. Remember, variance works both ways. Sometimes it's a very good thing. For example, your miners can get a lucky streak and find a bunch of shares, and the pool itself can get a lucky streak and find a bunch of blocks, resulting in you getting way more BTC than calculators say you should. Like I originally stated, if you can stand the variance, then p2pool will work for you.
There's a very good thread that compares p2pool to Eligius and BTCGuild. It shows that during the timeframe of the experiment p2pool has outperformed both of those pools. Check it out here:
https://bitcointalk.org/index.php?topic=416933.0