Don't get rid of your 50mm for it!!! The 50mm is so incredibly useful for a LOT of things.
I love my 17-50 f/2.8 but if you are using it for other things the lens distortion can definitely be a problem wide open. I get into trouble there often with it. I love the 28-75 a WHOLE lot more. For sports the 17-50 is fine, the distortion is rarely an issue, but portraits it's not so hot... Makes for some huge noses and bent lines. Fixable? Yes, but pain in the butt to fix all that in post. Rather not have it to begin with.