Crossroads: self-publish or traditional publish my new novel?

Over the last six months I have been very lucky to have had the time to write whenever I want. Part of the time, I was based in that famous Katherine Mansfield city of Menton, on the French Riviera, where the ions in the air I am sure helped me write a substantial chunk of my next book.  When I returned home, I had intended to go back to work, but finding a job took longer than expected and it is only now, six months after my last job, I am about to resume the 9 to 5 workday. In the interim, I have finished writing the book and have completed a substantial edit after finding a wonderful editor/adviser in Bronwen Jones (bronwen-jones.com) to provide the independent and wise advice a writer needs at this critical stage in a book's life. I thoroughly recommend her services.
The new novel is tentatively titled "Aftershock: a story of new beginnings". I'm not sure I'll stick with the title, but it will do for now. It's about how love endures, how two former lovers learn to trust each other again to find a new beginning and it's set against the backdrop of the Christchurch earthquakes of 2011. Bronwen helped me work through that plotline too! 
So I am now at crossroads decision: do I self-publish, like I did with my last novel? Or do I go back to Random House, who published my three earlier novels, (randomhouse.co.nz/authors/felicity-price.aspx) and see if they would like to take it on?
I'm thinking I'll try the traditional publisher first, mainly because it's so much easier to let them do a lot of the work for you. You don't earn so much per book, but you do tend to sell more books.
However, I'm not so naive as to expect Random to do all the work. Times have changed and even traditionally published authors have to go someway towards promoting and finding outlets for their books. My next move, therefore is to update my website and build a database from it. A new learning curve.
If Random turns me down, I've been down the indie author route three times now (with my last book and two from my back catalogue) so, with a database and interactive website up and running, it should be a comparative breeze. 
Meanwhile, it's off to work we go.