I have several riding boots. Leather soles are too slippery so avoid them unless they have rubber tacked on. I just bought some Otto Zone leather motorcycle boots for summer riding. Otherwise I have a set of cowboy boots and some harness boots. Also have a pair of oiled leather short engineer boots from
Leatherup.
You should always wear leather uppers with a reasonably heavy sole. If your foot gets trapped under the bike in a slide those kind of boots will determine whether you keep your foot or not. Forget sneakers, they pop off quickly and after that its shredded tendons, skin and bone.
You don't have to go outrageously heavy. A low cut boot like the Otto Zones will do the job, and remain comfy for walking.