I will be revisiting this work because of its superb organization and analysis of East-Central Europe. There is one small criticism I have of the work, namely that by distinguishing between liberal pattern states (Czechia, Poland, Hungary) and illiberal pattern states (Slovakia, Bulgaria, Romania), Vachudova doesn't create enough place for nuance in the categorization.
She rightly highlights that Czechia, Poland, and Hungary can often be called liberal in the 1990s and early 2000s, but as of 2022, the dichotomy doesn't really work. If anything we see Poland and Hungary spiraling into illiberal patterns -- and we'll before 2022.
For the narrativization of the text, this categorization (which is crucial to her thesis) works. And I enjoyed it as a result. Europe Undivided is an excellent analysis of the EU's passive (and active) leverage over East-Central Europe and the pursuit of democracy in the region in the 1990s.