Bulgaria's capital (at least the central part) is easy to navigate -- despite the street signs being almost exclusively in the Cyrillic alphabet. It's nice and compact, making it very walkable. It's not beautiful like Budapest or (somewhere I've yet to see) Prague, but it has its share of striking buildings.
One of the poorer countries in the modern Europe, Bulgaria has some stark contrasts. There are plenty of people begging, and those who've approached me on the street are either money changers or women trying to sell their services. Alongside this are the young from well-off families in their posh cars and the expensive international brand retail outlets.
Most people in shops and cafes can speak English, and there's a big German influence in the products on sale. Things are generally cheap. 1.5 litres of bottled mineral water costs the equivalent of 90 New Zealand cents, or 40 British pence.
One thing to watch out for.. there are plenty of loose paving stones ! Construction work is concentrated on building a new line for the metro train system, which means traffic disruption in places.