The Process Excellence Network has a post by Chris Gardner on best practices, When do you know a practice is truly "best"? The usual warriness of "best practice" discussion applies, but the author does a nice job of reminding people that there is really no superlative:
Finally, there is no practice that is best for all organizations or in every situation. In addition, no practice remains "best" forever, as business practitioners constantly find better ways of doing things. Benchmarking helps bring context to a set of conditions (e.g., demographic, environmental, cultural) that are best for a given practice.
Practices are what they are. If they produce the results that you want, they are good enough for now. The important thing to watch for is when your results start falling off (either because output drops or the market expects more or your competition does more). Having benchmarks, as discussed in the article isn't a bad thing. You just need to remember why they are there - they are proxy measures and indicators, rather than the core indicator of results.