All of the concerts I have seen at Universal I would consider real concerts. In fact it was because of the Rock the Universe event that I first came to Universal (being a huge Disney fanatic). Many of the bands I have seen play at Universal have put on better performances here than at other venues I have seen them play (the christian band Audio Adrenaline put on one of their best shows at Universal, and less than a month later played what was going to be their final performance in Miami which was terrible). As for the stages, until Universal build the Music Plaza, all of the performances were on temp stages, like the Hollywood stage which is still used and a smaller stage that was on New York street in front of Twister. Also, Disney has more than just the 2 icon stages, especially in the Hollywood Studios park such as the Beauty and the Beast stage, Premiere Theater, Lights Motor Action amphitheater and the Fanatasmic amphitheater which could all be used for "real" concerts. (Side note, the size of the venue does not matter for anyones performance. My favorite show this weekend was at Night of Joy in the Magic Kingdom with the band We As Human who performed on the small stage near Space Mountain).