Given that I find it difficult to tell apart the results from my chrome 50C and my FLE CF 50mm lenses any disappointment you will have will be down to lens variation in production, which is minimal, and lens physical damage moving alignments over its life and of course you may share my main barrier to superb results: the person pressing the shutter.
It depends what you are comparing to of course if you regularly shoot the 100mm f3.5 almost anything will struggle until you hit the 180mm then the apochromat. The close range correction only kicks in below 4m which is pretty close and I rarely find myself using it. I would suggest that "lacklustre disappointments" may stem more from unfamiliarity with wide angle lenses the popular misconception is this is a 35mm ,focal length lens equivalent, when based on the diagonal it is around 28mm which needs more skill to execute effective compositions, I don't like running those comparisons as correctly the frame ratios mess up these calculations but its good enough to explain the point, I hope.