opinions differ. i'd never claim to have been to *every* "walkable" city in the world, but i've been to more than a few that are commonly considered standouts in that respect and i'd hold boston's street-level exeprience up to (or beyond) those of barcelona, paris, san fran, london, shanghai, rome, etc. the weather presents challenges in the winter, of course, and like most u.s. cities (until recently) open-container consumption isn't allowed, but i'd say walking around boston in the spring/summer/fall pretty much can't be beat.With all due respect, although Boston certainly has better "walkable, street-level engagement" than most cities in the US, placing us above "pretty much any other [city] in the world" is a stretch for me, imo. You can get the experience Boston offers and better in *most* Western European cities, to say nothing of cities in Japan, Korea, Taiwan, etc.
Heck, you don't even have to travel that far. Canada and Mexico both have several phenomenal cities for walking and streetlife.