We had a 2-hour city tour in Belgrade (bus and walking) with Ana for a Ukrainian delegation. We all enjoyed Ana's company very much. She is just nice, knowledgable, helpful, with a great sense of hospitality and had arranged a perfect programme to show as much as possible of the city in a very limited period of time. She shared a lot of Serbian history, Belgrade sights and shopping tips ;)
If you decide for Ana you will surely enjoy the city tour.