I have asked a similar question so I am not an expert but I can offer some things to consider:
Why do you want to publish a book?
If you simply want your name in print, self-publishing sounds like the best option.
If you are publishing in hopes of reaching a lot of people, I would analyze how well you think you could promote your book yourself versus what exposure a traditional publisher could offer you. I have heard that some publishers "kill" a book and decide not to promote it so I would be careful about which traditional publisher you choose.
If you are publishing for the purpose of earning money, I think you need to analyze both options carefully. There may be hidden costs with either and risks with either.
Unfortunately I don't think your question has a straight answer. I think in some situations for certain people traditional publishing makes the most sense while for others, self-publishing is the best choice. It's a big decision. I hope you weigh your strengths, goals, and options wisely!