Nice 3* hotel, hard to give a balanced review as we had originally booked centrally located 4* hotel, but found out our booking had been cancelled in error when we arrive at 1am, so we did not book into Hotel Europe till after 2.30am, not a good start.
The a/c stopped working on the last night out of 4, and the Wi-Fi failed on the second night. Toilet extract fan did not work, and the kettle was broken, but as above this was a cheaper hotel, and we were reimbursed the difference, so you could argue we got what we paid for, though not necessarily what we wanted.
From a 2 minute walk to the centre of Sofia for our original hotel, we now had a 8 stops on a bus, and another 4 on the metro. But again, not the hotel's fault.