http://colin.mollenhour.com/2010/06/30/the-right-way-to-opti...
This has stats, again for whatever version Apache was up to decade ago (there was a while between releases).
> For my benchmark I ran “ab” (apache bench) since it is quick and easy but admittedly not the best for benchmarking overall site performance. In this case apache bench is going to under state the value of this tweak since one page load in a browser will result in repeated hits on the webserver, all of which will be affected by this optimization. So, I benchmarked on /errors/503.php so that the database is not factored but PHP code is still run. Specifically, I used $ ab -n 1000 -c 20 .../errors/503.php.
> Before: ~3000 requests per second (3018 max)
> After: ~4600 requests per second (5030 max)
> That’s a pretty nice improvement. Unfortunately it is only substantial with fast requests such as the error pages and static files but it should definitely reduce disk contention on a busy server and increase scalability, but probably not do a whole lot for user-experience on a low-contention server.
...looks to be at least +10% performance difference without .htaccess with basic static html. Probably more with many lines of rewrite rules.