That is what I have found also. I can almost shoot quite fast with out a lag in shots as I have regular batteries in a smaller back flash and I have to work at slower speeds for them. Another good rechargeable I find is the Duracell 2450 mAh
Also thanks to Benjiboy I did not burn out my camera by using the high voltage of the 45 CL 1 on my EOS 3
The 45-CL1 doesn't have high sync voltage. That is why it's called CL1 instead of the high voltage version CT1.