Although I agree you should remain true to yourself during performances, I do believe you must work to develop a character to make your magic effective. In order to truly make an impact on people, it's necessary to command respect and intrigue to a degree. Any working professional will agree to that. Emphasize your strengths and flaunt them as much as possible.
I believe that's what made the likes of David Blaine so famous to begin with. He acknowledged he was a quiet, deliberate individual and recognized how people responded to that energy. According to his book, he developed the character we see on television based off his strong qualities and personal experiences. What set him apart from his adversaries and copycats was that his persona was legitimately original to him and audiences believed in it. Everyone listened to every word he said and paid attention to every gesture. He commanded their attention and made them wonder what he would do next. Something can obviously be learned from that example.
Magicians should strive for originality. What makes tricks feel like magic? It's what the performer adds to them. I was recently at Denny&Lee's Magic Studio in Baltimore and Denny accentuated a good perspective. Anyone can do tricks. A MONKEY can do tricks. It's the role of the magician that adds the element of drama and intrigue into the equation. For this reason, I don't believe just merely being yourself can work universally. It's essential to add a and put major focus on a distinct flavor to the recipe. Everyone can add a original element to magic, and they should focus on what makes them peculiar and different and use such characteristics to their advantage.
The bottom line is that quality magicians succeed by accenting their personalities and character in their work. They set themselves apart from the crowd in order to gain people's attention and interest, but also keep themselves grounded in order to relate to their audiences. It's a fine line that deserves some thought and experimentation.
Hope this helps.
RS.