In theory, a 8' ceiling with 3' of pink stuff above it could be a good thing. But it all depends on what the overall room characteristics are to whether this single factor will be a good or bad thing.
Like so many threads, you cant single out one wall surface, ceiling included, and ask what to do with it not knowing what the total picture is. That means good freq responses and ETC's at a minimum. Otherwise, its all guesswork and any advice could just as easily make a situation worse rather than better.