Business needs and human factors ought to take priority when designing keys for a table. When you take those requirements into account there's no reason to assume that guids and incremental integers are equally valid choices or that either of them are always suitable. There are many factors other than benchmarks that could play a part in key design. How happy would hypothetical customers be with reciting a 32 character order number over the phone to your customer service desk for example?
If you add into the picture the need for real keys that people can see and use then the results of these tests and their relevance could be completely changed, e.g. will you cluster on the business key (AKA "natural" key if you must call it that) or a surrogate (whether guid or integer)? What patterns of access would use one key versus another?