Hey, i know i am new , before when you would read this don't think me as newbie.
Because only few people here know about paid CMS. and i am one of them.
You asked what are good things related with them :
1. They have richer UI experience,
2. They are just made for that , nothing else than what you need,
3. Few hackers know about them as they are paid, and hence less vulnerable to attacks, as they can't get what cms we are on,
4. Fast loading,
5. One to One support,
6. Feel something better as they are not going to cost you that much,
Looking forward for a chat .... as discussions always worth
You can check demo too if you want to select me, i am just new on freelancer but if you are going to talk about knowledge , i have passed more exams than anyone else present here