3.5 stars, but I'm giving it a half-star bonus on principle (like I did with For The Win). I would rather see more 3.5-star books with a diverse cast and well-thought-out SF worldbuilding than 3.5-star books filled with the same old stuff. 
 I think now that this world is built, she'll be able to unclench a bit and have more fun with characterization in future installments. The people felt stiff to me, the romance a bit rushed, the conversations a bit lifeless. 
 The world really carried this. I want to see more of the arachnid-based fauna, to say nothing of the landscapes outside the urban areas. There's a whole continent to explore -- I anticipate interesting things ahead. 
 Sandler is clearly smart, as the worldbuilding shows; I anticipate the human side of things will catch up fast, and we'll have a good, solid series on our hands.