I'm afraid you're right. I'd say this lens is going to be just as good or better than the 400mm F4L IS DO(when looking at the quality of the newest Canon lenses). Add that it's more versatile being a zoom. It has the build-in extender. All those things will make it a very versatile, yet fast lens for a lot of different photographers. Think about journalists, bird-photographers, wild-life, sports. It fits in almost every photographers wishlist if you ask me [] It doesn't fit in every bag or budget I'm afraid [:#]