Let's wade into the quagmire of publishers' advances to authors. They used to be a lot bigger, we know that. But in good times or bad, there is a certain thinking that goes into them, from the publisher's and the author's perspectives.
Of course, the larger corporate publisher has deeper distribution channels, wider networks. This has traditionally been a big plus for larger publishers. But in today's publishing, it doesn't matter as much with more books selling in non-bookstore channels, and largely online.
Half of your author brain is saying "I can see that I'm better off with a strong marketing publisher behind the book year in and year out," but the other half is saying "Grab the cash and the publisher can do what they want with the book--I've been paid!"
Answer these questions:
1. Where are my readers most likely to buy my book--in a bookstore or online? In paperback or as an ebook?
2. Where and how will I be marketing the book, predominantly--online or by speaking and traveling, giving workshops?
3. What do I need the publisher for? (editing, production, distribution, media access, in-bookstore presence)
When you understand your book in these terms, you start to understand what kind of publisher is most suited for you, and what your priorities are. You then understand how the advance will work within these parameters, and you will have a realistic grasp on how to make choices.
I'm a proponent of good advances for authors, but I'm not in favor of overpayment, for one good reason: When the author takes a large advance and the book does not earn out, that publisher will not touch your next book. The love affair is over. You can end up a one-book wonder pretty quickly. If you can take less on the first book and be sure to earn out, you pave the way for a publisher to support your second book, and to leverage up your advance and marketing support from the publisher. A better bet long-term.
You only profit when your publisher profits.