The flexibility, efficiency and ease of use in creating websites using WYSIWIG editing is great! It's also very easy to edit and update content if needed.
I've been working with Typo3 since version 4 was released over 15 years ago so it has evolved into fantastic product that can be adapted into almost any website or application you need. We are now looking at migrating to an NginX server but there really isn't anything about this platform we dislike - perhaps lack of support for PHP 7 (which our hosting provider hasn't upgraded). As an advanced level user who likes having everything under one roof, it makes my life easier as well as reducing time spent searching for things.