I owned the 28-85 for a few years and loved it, but eventually traded it in because I found it to be too big and heavy to allow always having the camera with me. I then used the tiny 45/2.8 for the next two years, until a few months ago when I bought the 35-70/3.4 zoom.
I find the 35-70 is a good compromise. It is small and light enough to allow me to always have the camera with me in a small camera bag. Also, it has a very nice macro mode, which is not available in the 28-85.
Although the 28-85 has outstanding image quality, I found it often quite hard to focus at the 28mm end in low light. I would crank the barrel back and forth, never quite sure if I had it in good focus or not. That annoyed me. I sometimes had to resort to scale focussing in those situations.
The 35-70 is easy to focus, and has slightly better image quality than the 28-85. I have a 28/2.8 to cover the situations where I need the wider angle of view.
If size and weight don't matter to you, go for the 28-85. If the size and weight is a problem, go for the 35-70. If you want to use a good macro mode, go for the 35-70.
I never used the 28-70, so I can't offer any comment on that. The main reason I didn't get interested in the 28-70 is because I prefer the one touch zoom. I don't like using a separate zoom ring and focussing ring. It isn't efficient. That's just my preference. Some people prefer the two touch zoom and focus.