I'm after some opinions on purchasing this lens. I'm after a lens to be a landscape & general walk around. I had been using my kit lens but it recently died so I've been pushed into upgrading sooner than expected. I will be using it on a 450D and I will eventually upgrade to the 7D, so it won't be on a FF. I've read great reviews from people using it on a crop body but just need that extra convincing that it would be the right choice, it's certainly not cheap.