I had a chance to try the lens extensively. It is much more versatile than my 17-28 f2.8 and it is at least as sharp if not sharper at all focal lengths. I found myself not changing lenses too much unless I needed something longer than 50mm in which case I switched to my 70-180.
HI there, nice video. Isn't this lens to long for hand held while vlogginf? 17-50 seems perfect for vloging, but I'm afraid it's to long and not comfy. :)