What does the software or service do well? This is one of the easiest service for uploading a website in a web server. You can easily manage it and learn in the process. I have used it with my students at college and is really easy to use.
What does the software or service not do well? I can say they don't have a good support for the free account service. In the last 6 years they got hacked 2 or 3 times and there wasn't an answer from them. So this isn't a good impression of their support.
What do you wish you had known about the software or service before using? I could like to know the differences between their services, because a site that got hacked several times in the last years makes me doubt. Not sure if the payment support is better than the free