Nikon's vintage 28's including the 3.5s are pretty good. I've carried out a number of ad hoc comparisons and it's my impression that the 2.8 AIS may be preferred, overall. Certainly in close but also at distances, the 2.8 AIS obtains very nice images; I've never noticed flare or ghost images to be much of issue. For several years (1970-74) I used Canon F-1s and FD lenses...the 24mm f2.8 had serious flare difficulties. In any case, as noted in various web commentary, Nikon's 28mm 2.0 is a close match to the 28 2.8 AIS at medium and longer distances. Surprising to me is the 3.5s AI/AIS, which perform better than I anticipated but for axis color fringing toward the edges beginning perhaps 2/3 out from center frame. Also, the 2.8 AI seems to provide, beginning at f4, high across-frame resolution beyond 7 meters or so. But these are mere impressions...hardly a quantitative assessment. My current vintage wide angles include 20 3.5 AI, 24 2.0 AI, 28 2.8 AIS, 28 3.5 AI, 35 2.8 AIS, and the 35 1.4 AIS though I've used several others at one time or another.
Not understood is Nikon's focus throw design choices. The throw for the early 35mm 2.8 AI (6 element) is comparatively long but very short for the late 35mm 2.8 AI. Then, the throw for the 35mm 2.8 AIS is extended, compared to the late AI version. Yet, the throws of the AIS versions of the 24 2.8, 28 2.0, and 28 3.5 are comparatively short with reference to the AI counterparts.
As Roland alludes to, I like the longer throw of the AIs though it isn't always this