I had this thought once when I had my Canon 1000D and both of those lenses..I.posted to several forums and the answer I got is to stay with those 2 instead of going for that superb allrounder..mostly because of the image quality the twins can offer over the 18-200..but I need a lens that can handle almost everything so I bought it anyways..guess what? It's a great lens..the image maybe whit soft on 200mm, but as u stop.it.down to f8, its reasonably sharp. So I say go for it..but that's just my opinion..and I'm a lazy dude