I love the face that we can edit our work. I write on another site and once it's published it done. If I happen to notice an error, such as a typo or any of the numerous things, I have to write a letter and ask someone else to fix it.
On Hubpages I can write about anything I want, even if it's just to keep my mind working. It is welcoming for new Hubbers in this way to get the feel of writing, what is good what is bad and then once they get the hang of it can go back and change their original Hub if they wish.
The forums are extremely helpful as well. If you need an experienced Hubber to answer a specific question, almost any time, day or night someone is on to answer it. The same goes for the answer section.
The comment section at the bottom of the Hubs allows the writers to know if they are doing a good job at writing as well. And helps to create more Hubs, with some of the comments alone.