wilderness - 1:49 am on Jan 11, 2013 (gmt 0)
My own "system"* is pretty much the same except that it also uses mod_setenvif and mod_auth-whatever-it-is. And I get along better with CIDR ranges, on account of having learned binary at an early age.
FWIW, I converted some of my mod_rewrite IP's to mod_auth (deny from) and CIDR's, despite the CIDR looking like pure gibberish and requiring six calculators and four website to convert to a comprehensible ten-finger-ten-toe format.
The reduction in file size thus far was 25k+ or an approximate 20%.