Judging by the MFT charts of the 24-70/4 - to be taken with a grain of salt as usual - we should see a marked improvement from the 24-105. At least comparatively at 24mm. Furthermore, at f/8 the new lens does seem to be on par with the 24/70 II. This should be good news to landscapers, isn't it ?
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_24_70mm_f_4l_is_usm
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_24_70mm_f_4l_is_usm
