What are the advantages / disadvantages of both?
Which of them would you use to filter comment that user a posting on a website?
kses has not been updated in 7 years now -- I think that's enough to take it out of the picture immediately.
However, the real question is: Do you need to accept HTML input in user comments?
Because if you do not, the correct solution to the problem is using htmlspecialchars before you echo the comments as HTML, and that's it. Nothing more is required.
Even if you need to allow users to format their comments, there are various alternative markup languages (BBCode, MarkDown, Textile -- this is what SO uses when you type) which are both widely used and more than adequate for the task.
Consider that you can even build Wikipedia without accepting HTML input.