I think that the experiment was good for Charlie for a few different reasons. First of all Charlie was able to experience life as a normal individual. As he became smarter he was able to talk intelligently to others. He was also able to experience attraction to another individual who was Miss Kinnian. He knew what it was like to have a below average intelligence level and he also discovered what it was like to be a genius.
There are also some negative aspects to this question as well. Charlie regressed. This was very difficult to experience. He went from being way below average to way above average. He had to deal with this. This must have been very frustrating and heart breaking.
In an aspect, Charlie was a perfect example of 'ignorance is bliss'. While the operation made him realize the world as he knew it was not as good or innocent as he had felt before, it made him more angry and unhappy. Though made fun of and treated derogatorily, Charlie was, in a sense, happy. He was pretty much alone, but had people he cared for, thinking of them as his friends. He saw the world without understanding its deeper meaning and the deeper he dwelt into that meaning, the more he sank into despair, alone. So the answer is: would you rather be super intelligent but unhappy and alone. or mentally retarded but happy. I would say what Charlie didn't know didn't affect him, emotionally. If he'd been normal (not above it) it would have definitely helped him. Because while Charlie was under average and below it, he faced abandonment and regret, isolation. All he ever wanted to be was 'normal' but all he got was anything more or less. I would say the experiment was not good for Charlie because while he became ashamed of what he was after he realized it, he was happy and bliss without knowledge. There are always some things in life that we wished never to have known. I think perhaps they should have brought down the operation to only make Charllie of normal intelligence, not more than it.