Hey Geoff - thought I'd could pipe up here as one of the lucky few to own one of your builds.
I recently upgraded from my 007MKiis to the 009s. A big step up in terms of cost, but absolutely worth it imho. Bigger soundstage, more detail and bass yet never sibilant or strident.
The only step up I can see from there would be the BHSE +009 combo (which I heard & loved at a recent head-fi meet). When my ship comes in... :-)
Bottom line: KGSSHV + 009: highly recommended.