Decent boots are great!
I started out with a nice pair of cross-trainers when I globe trotted. I quickly switched to Merril boots (well most of the time) to protect my ankles. Lots of foreign cities, public transportation, trails, and stairways can be rough, uneven, have potholes all over the place, and or have protrusions friggin' everywhere. I sliced all they way through to my sock once in Shanghai. My boots saved my ankles and even toes more than a few times. I suggest the boots if you can only choose one. BTW Asolo and Merril make great products!
Knuck