Ultrafires are a lot of things they don't indicate, a good example is the time I bought 12 Ultrafire batts, out of the gate 3 were dead and I don't think a one of them had the rated mAH printed on the batt. I stopped using them and switched to AW, so far they've far out performed the Ultrafire and Trustfire's by a country mile. Not to mention that someone is counterfeiting Ultrafires and Trustfires, it's turned into a crap shoot getting real one's.
The E-Powers are regulated because when this type of batt comes off the charger it has 4.2 volts on it, by regulating at 3.7 volts it stays there a lot longer than with an unregulated device. That's why you don't notice any decrease in performance longer than with an unregulated device.