I know that I want the reach to 70mm to match up with my 70-200. The questions are is the 28-70 better or worse than the 24-70, and is losing 4mm on the wide side going to make a big difference. When time and money allow, I'm going to compliment with a 12-24, so I will eventually be well covered. For now, IF the occasion arises that I need to go wider than the Sigma's allow, I can still use my kit lens. All comments and opinions are welcomed.