I currently have a Canon EOS 1000D and want to upgrade to a Canon EOS 60D next month. However as I already have the EF-S 18-55 IS kit lens, a Canon EF-S 55-250 IS zoom and the Tamron10-24 super wide angle, I am agonising over what lens to go for as a possible replacement for my 18-55 as I am advised it may be not ideally suited to the demands of the 60D. I have been looking at the Tamron 18-270 and Sigma 18-250 as "do it all" lenses but undecided as I love my Canon 55-250. Getting one of these however would remove the constant changing of lenses as I have to do now whenever I want more distance. Basically are the Tamron 18-270 and Sigma 18-250 lenses any good and is there a better option for me at around £400 from Canon. I notice also the Canon EF-S 18-135 as a cheaper option but really don't know what to do. I would appreciate any quality advice from anyone on this to help me.