I posted earlier that the car will lose something with age/abuse/repairs. I did not include some caveats, which others have mentioned.

Make sure that the bars are good. I do not use a rate checker, I just replace old/abused bars. The reason for this is that bar rate will not usually change, as rate is a function of material and size. But... ... response of the bar will change on a molecular level. Too much detail there for a message board.

Shocks. Have your shocks dynoed and tuned by a good shock builder. I have had new shocks that overlapped on the rate numbers, i.e. a 3 compression shock that was stiffer than a 4 compression by the same manufacturer. This was driven home one night when I was pedaling a loose car in TT, and I changed shocks from a 4/10 non adjustable to a 4/10 adjustable by the same manufacturer. After the change the car was driveable wide open all over the track. Eye opening experience. I now use a good shock builder and know what my shocks are. My car feel has also progressed with my shock program.

Without consistent shocks and bars I probably would not notice the change in the frame.