It might have had to do with my having read several really dark, depressing, painful-to-read books lately, but this book was just so light and fun and refreshing I couldn't help but love it.
It's just a very sweet story. Yes, disbelief must be suspended by more than just the time-travel premise: Alexander has a stranger appear in his house and says "hey, you look just like my lover who disappeared! What's that? You're from the future and you're in love with me? Well, shucks, you better hop right on into my bed, then!" It wasn't enough to pull me out of the story, just made me chuckle a little at the time.
If you're in the mood for a light, sweet, improbable romance with a little dash of historical. This one is definitely fun.