This started out slow, and I was in the middle of deciding I didn't like it because the alien race while biologically very different was culturally too similar to 21st century Americans for me, and then I got hooked on the plot, and ended up staying up to one in the morning to finish it.
In the end the similar cultures worked really well, because they just underlined how very very difficult communication through a language barrier is, and leads the characters up for a bunch of assumptions that came back to hit them later. It turns out part way though that the aliens are actually slightly more relatable than humans who have lived in deep space for a long time, and that's set up beautifully.
I really loved the relationship between the two point of view characters, how their friendship grew and overcame both cultural and trust issues. The final few chapters, as previously mentioned, were absolutely gripping because I was just so damn invested in them all being good/ok by the end.