Generally speaking, the roadsters got better with each successive year, but I believe there are a couple of exceptions to this, and one is quite serious.
The single piston brake calipers which were introduced along with the 35mm forks for the XS650D, are in my opinion, a retrograde step. They may be lighter, but they seem to lack rigidity to me.
The other thing I don't like, although it is only cosmetic, is the cheapo looking idiot light cluster that came in the same year.
Not a performance issue, but the thing just looks cheap and nasty to me.
The Special got a much more classy looking set up when it was launched.
Otherwise everything else bad got sorted.
The twin cable carbs, the fragile fuel filler cap, the micky mouse brake lining sensor etc.
A pity they didn't fit a grab rail until the final year