jbhswim wrote in post #11079450
Hey guys, just wanted to check in and see what the general consensus is..
I'm a Sports Shooter, and need to grab some faster glass for the upcoming low-light winter months. Like many, I'd love to save some $$ and go with the non-is, but don't want to sacrifice any sharpness or IQ.
Are they in the same league even though the non-is is an older lens?
Thanks in advance..

BTW: The Mark II is way out of reach...
I went through this similar scenario for a different form of fast-moving action, which is belly dancers. I decided against IS, because it does not help you stop action. It can help keep the viewfinder display a less jumbly as you're panning around to capture the action, but it's otherwise completely useless for stopping action. Good hand-holding (or a monopod, perhaps) can do wonders though.
The 70-200mm f/2.8L IS USM is pretty tough, but it's not indestructible. Mine lasted about 5 years before the IS system got very wonky, and then this affected the regular AF. After examining several years of EXIF data for belly dance festival events on lighted stages, even though some gigs were low-light, f/2.8 was not the most often used aperture -- it was more like f/3.5 quite a lot. As a result, for this environment, the 70-200mm f/4L USM (the non-IS f/4 ...) became my workhorse lens -- and it was very favorably priced. If you're doing fast action outdoors, it would seem like you have much more light available than the dim theatrical lighting. I generally work Tv = 1/160 in this environment. Of possible importance, it should be noted that the f/4L is significantly lighter then the f/2.8L. It has made a tremendous difference for hand-holding, particularly for multi-hour gigs. Just picking up my (though br0ken) f/2.8L freaked me out the other day ... it's quite heavy.
Good luck whatever you decide, and hope you grab some great action shots!