Used uber in Baku and Bucharest in July.

In Baku, Google maps has a bad database with no house numbers which makes navigation a challenge. Once I got a Kia Rio with a broken windshield. Another time was a recent Mercedes sedan so YMMV.
Also I imagine there may be a language barrier due to bass GPS data.

In Bucharest going from the city to the airport things were fine. Had trouble getting it from the airport.

I use it extensively in Lisbon and so far have not had better service than here.