I don't know if you know or if you did and it didnt help you but they have a thread for this:
Well for one the STH14 has a shitty toe piece on comparison to the STH16. I would look into the STH 14 Driver, which is exactly the same as the STH16 but with the good driver toe piece. Also, the older 914 Labs are the same as the STH14 driver which skis.com sells for $200/159.
STH12/14 toe is just a reinforced Z toe piece which have been known to explode spontanously although i've never seen it happen i've heard of quite a few instances.