I would like to make a recommendation based on my experience.

When I started mining over 2 years ago, the one feature that was missing from slush (bitcoin.cz) was an average earnings per 24hours period metric.

Don't underestimate the power of that one small metric, as a small mining outfit monitoring 6 rigs, it provided me with a the feedback I needed to make mining worthwhile.
As a result, I chose to mine with BTCguild over slush.

I will guess BTCguild's success is largely to do with their UI and the "all powerful" average earnings per 24 hrs feedback.
In the light of there success, they are not following free market principals I have so come to admire about Bitcoin, but are now penalising usurers for there success, so I have swung back to mine with slush.

My biggest disappointment is I don't get any average per 24hrs earnings feedback, I am so disappointed I am considering paying the higher fees on BTCguild just for that little metric.

So as a plea, please add an average per 24hrs earning to the "My account" page.
thanks,