My answer to that question is that I actually trust the personality I see the least of everything I pick up. Some Dommes may actually post in their "real" voice, but for the most part my experience tells me that they are role playing their Domme character when they are putting together marketing material, which is what websites & blogs are about.

There are more glimpses of personality in social media interactions with other Dommes, friends and long-term clients but again you have to dig through the marketing posts and interactions with subs they don't really know to feel it out.