Demos are the lifeblood of an actor
When I produce a demo, it's important to have a variety of different spots that represent the genre that your demo is being produced for. For example, if you have a commercial demo you want to make sure that you have a variety of different industries that hire commercial voiceover represented in that demo. That way if your demo sits on your website or you submit it to a roster there are a multitude of different styles and different industries that your voice is heard in. That way it can attract buyers in that particular market.
Think about your voiceover demo, does it showcase your range and abilities and still stay within your brand? Your VO demo should have a variety of different styles and intentions, and yet stay true to your abilities and the genre you are working with.