Hey... I'll be up grading my lenses in a month or so and am looking for opinions.. I now have an efs-17-85, ef 70-300 is non L, ef 28-135is and 50 1.8. I wll pass these on to my daughter who wants to upgrade to a dslr.. I have a 40d, and shoot my grandaughter and landscapes and pretty much anything that moves or flies. I'm thinking of an efs 15-85 for walk-around and an ef 20-200 f4 is, and a 100-400.. I know the 70-220 2.8 is eveyone idea of the best lens but I don't make a living shooting and as much as I would like to have the best being retired wont justifiy tying that kind of money in something that would be revinew producing.I know the f4 is also a great lens and I do have a flash if needed. I have access to airshows in this area of Florida and the 100-400 will work there. Thanks guys and gals for your opinions Perk