This is pretty much what my experience was reading Shanghai Girls. Two sisters living it up in Shanghai in the 1930s! Then they move to the US and struggle to make ends meet through the 1940s. And deal with the racism of the Communist scare in the 50s. It all sounds so fascinating. But it just didn't work for me.
The book did have its good points. I really enjoyed learning about the high-flying lifestyle of the Chinese middle class between the wars. I had never heard of the "beautiful girls" who posed for commercial artists in China in the 1930s, whose likenesses ended up anywhere from ads for matchsticks to (later on) propaganda for communism. I also didn't know much about the conditions for immigration into the US in the 30s, and just how blatantly racist the system was. It never fails to amaze me just how horribly western governments treated non-whites for so long. And seeing just how deeply the Red Scare infiltrated people's everyday lives (especially those with a direct link to a Communist country) was eye-opening. Really important, fascinating stuff.
But gosh, the characters did not do it for me. The two sisters, Pearl and May, were hard to know and not very likable. The story is told from Pearl's point of view, but she is not a very dynamic character, and it was a little boring to spend so much time inside her head. She was scared of everything. (Granted, much of it with good reason.) And her sister, May, was so self-absorbed and spoiled that I didn't want to spend much time with her, either. The other characters were fine, I guess, but didn't stand out as having distinct personalities. Really, the book seemed to be more about all the suffering and hardship the characters went through rather than their development into strong and individual people. This is how I felt when reading Snow Flower and the Secret Fan, too - I just felt like all the characters kept me at arm's length, and as a result, I just never felt emotionally connected to this one.