There's something delightfully overwhelming when every five meters of wall is emblazoned with a scroll saying what fantastically historical things happened on-site in 1573. Every sight that you could ever want to see in Graz is a ten-minute walk from each other, unlike Vienna which has sprawled out to a fairly massive domain in order to accommodate Hapsburg Palaces and gargantuan churches.
When I picked up a tourist map with a listing of sites, it was hilarious how they didn't even expect anyone to leave the Old Town. Mariatrost Basilica, only about a five minute bus ride away was listed in the "Outside of Graz" section. Five minutes away from the Inner City in Vienna would get you to the Inner City of Vienna.
Graz is compact, yet doesn't suffer from overcrowding either. The ground level of every single building hosts an international shopping experience (United Colors, Salamander, H&M), café, or bar so that tourists and residents alike are off the streets—not that it would matter because only street trams are allowed in most parts of the Old Town.
The most surprising thing is the utter ordinariness of most of the facades which house the city's greatest treasures. With the exception of Schlossberg—a castle high upon a mountain which stands tribute to every Cathedral ever, you can just randomly walk into a door and find inside an ancient church or 30,000 pieces of battle armor with none of the fanfare that accompanied the Kunsthistorisches and Naturhistoriches museums in Vienna.