I did try to search to see if this had been asked, but didn't see it in the list. So here goes. I purchased the Canon 17-55 a few weeks back to go with my 70D and have been mostly happy with it. However, most of my shots lately have been at indoor gym's with fairly low light. This pairing doesn't work as good as I hoped in that scenario. So I've decided, in the next couple of months, I'll be moving on to a 6D or 5DIII. I will also be keeping the 70D as a backup/secondary for whatever it may be more useful for.
Since I'm still within the 30 return window, I was hoping some of you could give an opinion about returning the 17-55 for the 16-35 or something similar. Keep in mind that this is currently with the intention of shooting basketball and volleyball in low light. If only the 17-55 would work on a FF I'd be fine with it. One of the big questions on my mind is the IS of the 17-55 and the fact that the 16-35 doesn't have it. In fact, I don't own a lens that doesn't have IS and never have. I know this change will also affect the focal range, but I'm not as concerned about that as I am clarity and sharpness.
Lastly, the 24-70 is an option, but on my budget its an extremely expensive option. I could much easier absorb the cost of the 16-35 than I could the 24-70.
Any constructive help would be appreciated! Thank you!