After hauling around the 100-400 4.5-5.6 L I rented for this week, I decided that L glass is the bomb diggity. The pictures are so crisp it's ridiculous. I want to replace the shit, err kit, lens and thought a EF 24-70 2.8 L would be about par to replace my current 18-55. Am I really going to miss anything with that 6mm gone on the lower end? I doubt it, but figured I'd ask. Any opinions on the lens are much appreciated.