In major tournaments today the tables are very level on average, probably better than 60 years ago. The slower cloth back then helped to hide non-flatness. When Simonis became the standard for tournament cloth I think it was a problem for the installers to get the tables really level. Diamond seems to have solved that problem.Did older tables seem less level? Also, I know that on faster, newer cloth, balls will slide in. Maybe older, slower cloth wouldn't allow as much slide?
I think the old cloth was just as forgiving on nearly-missed shots. I remember seeing Caras in an exhibition in 1975. The main thing I noticed was how many shots he played off the near jaw. At the time I thought it was a defect in his game but now I think it was just his way of making the shot fuller (for shots along the rail) so it was easier to control the cue ball. He didn't miss.