I cannot find it now, but I recall reading recently that Rewrite, while powerful, is demanding on system resources.
If you were to use Rewrite is a method for dynamic virtual hosting on a large number of sites, could that cause a significant problem on system performance compared to mod_vhost, or some other virtual host method, for the same amount of virtual hosting activity? Is there an rule of thumb or algorithm to use your anticipated usage to plan and pick the best technique?
