It's a tough one because people's sensitivity thresholds vary so much for these characteristics. I had one beer that was awarded first prize at a competition, the judges raving about the clove/banana balance. A separate (skilled and respected) judge tasted the beer later and didn't detect any banana.
It might not be perception thresholds so much as an aging problem. Hefes are an incredibly delicate style and esters are one of the first things to drop as the beer ages. If your hefeweizen is more than a4-6 weeks old, unless you've stored it ice cold, it's not going to be a good as it was.