Some spoilers below
This was better than another book I'd read by this author (One Greek Summer), but still had a couple annoying aspects that keep me from giving it a higher rating.
The best part was the setting. Who wouldn't love a story set on a beautiful and idyllic Greek island, especially Santorini? I've been to Santorini several times and she did a good job describing the scenery, the food, the smells, the sounds, and the people. It was definitely a bit of escapism.
The storyline and characters were good, but had some weaknesses. I appreciated that Lottie wasn't your typical woman-in-a-loveless marriage, or mom-with-3-kids -- she was career-driven, absolutely fine with having no children, but of course she was a divorcee who was pining for love (after all, this is chick-lit). And the concept that she decides to go search for someone she connected with briefly, but strongly, as a child was interesting, if far-fetched. Reading the author's note at the end gave more insight into what that storyline was chosen.
The part that made me groan, though, was how utterly ridiculous it was that within a couple days of Lottie finally finding the boy's family and learning his fate, both of his brothers hit on her. Then after the predictable tension between everyone, she falls in love with one of them within a couple weeks and decides to up and quit her job to move to another country to live with him. Perfectly romantic, but utterly unrealistic.
One last note about the dialogue - I was annoyed by this in the last book, and it was the same here. The author is British, and most of the characters also are, so it makes sense for them to use British vernacular -- but it's not common for a Greek to use some of the terms and phrases she had them using, unless they'd spent time in the UK or around people from the UK. It seems like a bit of lazy writing to me. If an author wants the characters to feel authentic, they should be written using the appropriate vernacular and slang.
Overall, I did enjoy this book for what it was - a bit of light, easy, romantic escapism. I read the entire book on two international flights, so it helped pass the time.