I have a chance to get a good price on the PB-E2 for my EOS-3. What is the frames-per-second boost for the EOS-3 and what other benefits would I get from it? I shoot a lot of flash photography with the 550EX (not necessarily why I want the PB-E2) and was wondering if the battery life is better that just the camera alone. You can use Nickel Hydrides can't you? That recharge ability may be worth it all together. But mainly what is the performance increase of combining the 3 with the PB-E2?