I have recently used this lens for landscape and seascape images in mostly good outdoor light on two full-frame cameras, namely the EOS 5D and EOS 5D Mark III respectively. Although it covers a range of focal lengths I already had mostly covered by three prime lenses, I did not previously possess...
Robust and impressive build quality with smooth handling; relatively lightweight; reliable autofocus; familiar vibrant Canon colours; Well priced (at least by 'L' standards)
Very weak corner resolution at 17mm below f/11 on full-frame; The bulbous and ugly lens hood is large, obtrusive and awkward to pack unattached