With a zoom like the 24-70mm, be sure to apply DLO (Digital Lens Optimization) when you do your Raw conversion. If not, you'll not enjoy the full potential of your lens. If you're not aware of DLO, it's part of DPP (Digital Photo Professional) that ships with all the Canon DSLRs. Lightroom has a similar function and it's a basic part of DxO Optics Pro.
DLO will automatically correct for geometric distortion, vignetting, chromatic aberration, softness, etc. at every aperture and every focal length, with every camera body.
Don't use zooms without using DLO.