I ride a Breezer Villager. Same basic bike, but mine's a step-through, so 20 tooth rear cog. Breezer does the cog bump as a standard thing on the step-through models, and most shops should be able to do the swap trivially. The stock gearing is not aggressive at all, even with the 18t cog. I do a lot of riding with heavy loads (30-60lbs) and I like my knees, so it hasn't been worth it to swap up to an 18t for me. Yet.

For most riders, either stock gearing will be appropriate. If you're typically cruising in the 60" range already, and you don't plan on heavy loads, I don't think I'd gear down. That's pretty much the cruising gear Breezers are designed for.