[Exim] Exim on FreeBSD w/ vm.vmiodirenable=1

Hi folks,

Has anyone done any playing around with Exim using split_spool_directory
on a FreeBSD box with the vm.vmiodirenable tunable[1] set to 1?

While the hit on memory is pretty hard, it seems like this would be a
winner on a hard-working dedicated mail server with large queues and
lots of memory, provided the memory wasn't constantly at a premium.

Ciao,
Sheldon.

[1] vm.vmiodirenable allows directories to be buffered in the VM page
    cache.  It's disabled by default, since it's unlikely to be
    beneficial for low-memory systems.  When disabled, only a small
    number of directories is cached.