If you haven't read this yet, please do (best practices for URLs).
So, it's a combination of things. As Devi Allen said, less is more. You want to use (and not over-use) descriptive words, separated by hyphens, "keeping URLs as simple, relevant, compelling, and accurate as possible". "To correctly render in all browsers, URLs must be shorter than 2,083 characters."
Which is better, your URL or your competitors? They sound pretty close based on your description but what matters is the actual words used in the URL, the site structure represented by that construct, whether the words truly represent what a visitor will find on the page, and whether the page content will provide visitors with the information they came looking for. URL length is but one of many factors that go into determining whether you or your competitor will rank higher.