The current 007Mk2 is excellent and an upgrade over the Mk1 really (once port modded) and that would still be my top choice. The only ones which can reproduce the full range without any issues. The top end on the current Mk2's is improved and amps like the Carbon means they are not dark at all.
The 009's are too bright and even when fitted with EP-007 earpads they are just grating to me. The earpad change has helped though, they are now more dynamic and not as uninvolving as the 009's have always been.
As for the 009S's, they are growing on me with the older 009 earpads plus I did some small tweaks to improve the sealing. They are still bass deficient but at least the top end doesn't make me want to cut off my ears... It's nice open top end and with the older pads they have a bit more focus which the stock setup really lacks.
While I've been digging around in the 009's (both sets) I just wonder why Stax did certain things. Why isn't the housing more substantial? Why is that crummy glued on bit next to the cable entry? Wasn't there some better way to make a baffle than this hackjob?