Been getting the itch to add a new lens to my collection, and I have been thinking about where I want to take my photography, and portraits and sports seem to be where I'm leaning these days. Now my question is, has anyone here had any experience with this particular lens, especially say on a 40D or similar body? Also been wondering too, since this is a bit longer of a lens, about a monopod for it, eventually if I find that I can't hold steady enough in lower light, does anyone know what tripod collar it uses? I've googled the crap out of it and can't seem to find any info on it. I've read that the one from the 70-200 f/4 fits it, but I can't seem to verify it. I'm assuming when I hit up B&H in the coming weeks they will know, hopefully. Also, reason I've been looking @ this lens is that I was looking @ a 70-200, but I realized that when I rented the 2.8 IS version, I spent most of the time @ 200, I figure why not save money and get the prime 200 for cheaper and with better IQ (supposedly). tl;dr - anyone with experience using this lens on a 40D, what tripod collar does this lens use, and any other advice?