I like that it's easy to use as well as being able to customize everything you want! It has been very helpful in creating courses for our team at work since we are all remote employees working from home so this helps us keep up with each other while also allowing everyone access via their own device of choice (laptop/tablet).
One thing i dislike about knowledge centre lms is how long some modules take to load sometimes which makes me wonder if they're really loading them or just taking forever before showing anything? Other than those two things there isn't much else wrong. We have used KCLM throughout my entire career now but when one person left suddenly had no way to send out emails without having someone come into office every time because he was an admin who did nothing besides check email constantly haha. This solved his problem though by giving him something specific where people could go directly through kclm instead of sending multiple different mails.