So I am wondering, does the effectiveness of IBIS decrease as the focal length increases? I haven't tested this theory, but my 7-14 and 12-35 are wonderful. I love those two lenses from every standpoint. However, I am Luke warm to the quality I get out of the 35-100 and unhappy with the 100-300. I know it would be easy to test, but just no time right now. Anyone looked at this? Or am I way off base.