I bought a used 35/2 AF-D in 2002, and it served me well until summer of 2014, when the diaphragm quit stopping down. Early production run 35/2 lenses were infamous for oil on the diaphragm blades causing a gumming up of the mechanism. Not sure what happened to mine...it occurred one day, right in the middle of a shoot. So annoying. I have always liked the 35mm focal length; it is a semi-wide angle look. I find it VERY useful for social photography. It's not nearly as wide as 28mm is, so it doesn't make everything "quite" so far-away looking, the way 28mm does, and which 24mm really does. On FX, a 35mm lens is very useful, even for portraits if used carefully. Sue Brice favors the Canon 35/1.4-L for much of her portrait work, so you can check her site out and see LOTS of people pics done with a 35mm lens on full frame.
28 and 35mm are two decidedly different length; neither is better, neither is worse. What I like about the 35/2 AF-D is how small and light it is, and the way it renders things. Again-semi-wide, without the steep drop-off to the background, and without edge distortion. It doesn't create that wide-angle-y look, and it works well for parties and receptions and a lot of landscape type shots.
If you need a 28mm lens, the 35mm lens just is not a substitute. The two lengths are actually quite different in what they do.