This is my lens line up and it has one glaring poor example which I need to replace. I have a 40D and a back up 10D Tokina 11-16 f2.8 Tamron AF18-200 f/3.5-6.3 :banghead: Canon EF 70-200 f/2.8 L IS USM Canon EF 70-300 f/4.5-5.6 IS USM Canon EF 100-400 f/4.5-5.6 L IS USM Canon EF 400 f2.8 L IS USM Canon 1.4x and 2x TC's The Tamron needs to go (the IQ just sucks IMHO). My thoughts are to go with either a walkabout lens of the best IQ in the same somewhat range or just fill the 18-70 gap with again the best IQ avaiable. Discuss!! (Overlaps in focal length allowed, just give your reasoning and examples if you have some). PS I would like to be able take three of this lens lineup for a travel kit ( considering airline travel and baggage limitations) and cover as many bases as possible.