If you don't need the IS, then the 70-200mm f4 (non IS) version also a worthy contender, optical quality is spot on, (even with a 1.4x TC), so I wouldn't take these optical test as set in stone, yes the 70-200mm f4 IS is a good lens, but have been happy with my f4 and f2.8 IS versions when it comes to aviation and motorsport photography and heard good things about the f2.8 IS MKII, but that lens is way too over priced.