Anybody familiar with the older 80-200mm 2.8 L lens? I've been seeing them pop up and was thinking of getting one. My friend says it's not a USM lens but about as quick and quiet as a non ring USM motor. A few people recommended I buy a Sigma 70-200 2.8, but I was kind of worried about the quality control on those--especially used. And supposedly the 80-200 sounds like it might be sharper. I'd actually use it in darker, indoor settings at events where people would be speaking at a podium or on a panel. I originally thought the Canon 70-300 IS USM might work because of the IS and reasonable price. I'd love to get a 70-200 f/4 IS but that's a bit out of my range at the moment. My third choice was a 200 2.8 prime. Many of my shots would be somewhat predictable so I could make a prime work. Thanks.