For example, a Compac F USB miner can generate about 300 GH/s at 12W, but that can change up or down depending on the frequency you're running it at (and also assuming you have enough Amps per USB port).
With the Apollo BTC you can get about 2.1TH/s at around 120W, but of course that can also move up or down.
I think that a site would be fine with listing the hashrates and profitability rates of only the default frequency i.e. assuming a user doesn't try to tune a miner by using different frequencies (using official or unofficial means) - since that kind of list with all possible frequencies and configurations would inevitibly become out-of-hand.