The 24-70/2.8 is the 2.8 version of the 24-105 f/4.0.
Just the same as the 24-105 is the f/4 version of the 24-70/2.8.
I know that might seem a bit strange, but there is only 1 f-stop difference.
um and 35mm of focal range which happens to cover the important 85 to 100mm
Are you going to say that the 5mm difference between the 16-35 and 17-40 is also important?
nope of course not but the 16-35 vs the 17-40 have many more differences other than 1mm wide and 5mm long i dont like the 24-70 i'd rather use the 16-35 on a 1.3 crop and a 70-200 on FF gives me effectively 20mm to 200mm all at f2.8 the gap in the middle use feet zooming.
I dont know i really like the 20mm focal length for some reason much more than 24mm cant explain it other than just personal preference but i like that range of 20-48mm its really nice and both lenses zoom internallly
maybe i could be tempted to the 24-70II if it lives up to its mtf chart but at the moment 16-35 is one of my favourite lenses