I'm in the process of planning a singlespeed build, and one of the dilemmas I'm having is which tires to use, and how they affect the gearing. My goal is 73 gear inches. According to the gearing calculator I've been playing with, I can get near-identical gearing with 700x32 tires and 46x17t, and 700x37 tires and 48x18t.

Tire sizing standards seem to be a bit fluid, and I'm trying to wrap my head around the relationships between the different nominal sizes - specifically, the Schwalbe Marathons, which have "700x35C" printed on them, but also have "37-622" molded into the sidewall. From asking around, I've gathered that the inflated width on a 20mm rim is just under 35mm (which is great to know for fender/frame clearance), but what about the height, for determining gearing?

The ultimate question, though, is this: All else being equal (tire brand/model, rim size, frame, gearing, etc.), would you rather ride the bigger tires or the smaller ones, and why?

In this case, it'll be used for all-purpose riding around the Boston area, primarily on paved surfaces with varying degrees of roughness. My main bike is a geared Bianchi Volpe with 32s, and I have no complaints about those, but I'm looking at frames that allow for larger tires, and am wondering if it's worth taking advantage of this extra clearance.