The reason we built a bespoke control panel is because cPanel doesn't allow for load-balancing and autoscaling in the way we use it. With 20i your site isn't restricted to one single server, which is how cPanel is configured. It uses the whole datacenter's server resources as needed and scales automatically. So you're not affected by spikes in traffic, or what other people are doing on the same server. There are many other advantages. For example, it gives your customers a better user experience without being too unfamiliar. Another would be that there are no licensing costs, - no matter how many customers you have!