In general, it sounds like readers can't put it down! John Irving praises the book at Amazon.com, so probably everyone who loves Irving will love this one. Reader reviews give away some main facts--twins, mother dies in childbirth--so these must not be spoilers, and the mix of uplift, humor, and tragedy does sound like something Irving would write, and therefore like!
I am reminded of The Stone Diaries, by Carol Shields, because that's the way my brain works. And "The Stone Boy," a story by Gina Berriault, that I finally got hold of in a collection titled Women in Their Beds.
That's enough mind twirling from me. I am off to glitter at A Glitterary Reading! (I am glittering with rhinestones and sequins. I forgot to put on the glittery nail polish....!)