Alright, I'd like to hear from people who have some experience with the Canon 70-200mm L lenses. I'm at the point of buying my first set of high quality lenses. Like many people, I've decided on getting one of the Canon 70-200mm lenses. Having used the Canon 75-300mm with no IS, I realize that lenses this long really need to have IS to be usable hand held at the longer range. What I'm having trouble with is deciding between the f4L IS or the f2.8L IS. Yes, money IS an object. A very large object. The f2.8L IS costs $500 more than the f4L IS. So statements like "Get the f2.8L IS because it's a better lens because it's a stop faster" don't help me any. I realize that the f2.8L IS is better. It also costs 50% more. What I would like is for people to weigh in on the value of the f2.8L IS (performance vs. cost). Have you used both lenses, or at least have experience with shooting both lenses? Is that extra stop REALLY worth the 50% price premium over the f4L? I will use this lens for: 70% wedding, 20% portrait, 10% indoor sports. 80% of these photos will be hand held, 20% tripod. As you can see, 100% of the time I will be taking photos of (moving) people, which is why I'm leaning toward the 2.8 (IS doesn't freeze moving people). Also, for the wedding and portraits, getting very shallow DOF is important. Additionally, many times the photography situations for weddings are very low light. So you can see that I do have some use for that extra stop, but I'm struggling with justifying the extra $500 that stop costs. Opinions? Thanks!!!!!!!!!