Check your return from the pool, not what the miner says.
All that matters is the return from the pool vs the cost of the extra energy used.
If you make more than its costs then its worth while overclocking.
The problem is that I have no baseline to check against.
Also, since I'm on Bitminter (PPLNS) it is hard to run for a while at one setting and then change to another to compare because of the varying CDF.