I've found PageSpeed Insights (https://developers.google.com/speed/pagespeed/insights) to be very helpful. It offers suggestions on how to improve the performance of your site, based on the potential for improvement. By benchmarking your site against others in your industry (or top performers in other industries), you can compare not only the overall PageSpeed Score, but you can identify how the suggestions differ.
This enables you to identify possible competitive advantages/disadvantages. For instance, if you receive a high priority suggestion that your competitors have already implemented, you may be at a disadvantage; the severity of which dependent on the resources required to implement the suggestion.
