What I for one hold against Real is what it did to my OS 8 and OS 9 systems. Taking over filetypes that ALREADY were usable--like wavs and even text files!--and then trying to open them, making them LESS usable than before. In fact, it took over filetypes it could NOT open, making those files temporarily useless. And trying to reverse the whole mess was a huge labor.
Now, OS X apparently does not allow Real to perform such nonsense. But I just saw what Real did to a friend's OS 9 machine last week, and am reminded yet again of how I was burned.