I own both lenses, the 24-70 II is my favorite lens out of my whole collection followed by the 70-200 ii. Those 2 together are the best combined. The 24-70 II has the prime lens quality/look to it on the images. The f4 is is also great, but the image sharpness isn't quite as good as the 2.8 II. If iq isn't a priority nor speed, then the f4 is a good choice. Otherwise 2.8 II should be your choice if it matters. Macro feature on the f4 is pretty good too, although I have the 100mm 2.8 that I use for that. If you get the 2.8 II, you'll be set for a really long time in terms of a standard zoom lens. Bokeh is excellent btw.