Does anyone have a Roadie canine safety harness for their Boston? I'm about to order one online, but I don't want to get the wrong size! Griffin's right at the edge between 2 sizes and I'm afraid it'll either be too small or too big. I was wondering if anyone knew if I should err on the larger or smaller side or if they tend to run big or something.

Here's one of the websites that sells them just for reference/illustrative purposes:

lookie here!