I've tried cPanel, DirectAdmin and Plesk on my servers. As user, I was happy about every CP I mentioned here (Plesk is my favourite though). When I'm ordering a server to host my own sites, I prefer DirectAdmin or Plesk, I save few dollars that way.
I used to run web hosting company for a year. We had more than 1000 customers. First of all we started with Plesk, we also had DA on one server. Most of customers were quite happy about Plesk and DA, but we lost some customers becouse we had no cPanel hosting to offer. I learned that cPanel is the best choice for hosting company. Actually, you may lose some customers if you'd choose other CP, since most of people who are looking for hosting thinks that cPanel is the best.