I stayed several times in the Zenith. Knowing many of the rooms and the appartments at the top floor I'm happy to say that it's a great hotel. It has the ambiance of a family ran hotel and they are very forcoming. They (and many others ) made my staying in Sofia a success and gave me a homely feeling.
Service and all other are very good.
See you soon. The dutchman from appartment 1. ;)