My Meikon housing has been working well for me. But, they only make housings for a small number of cameras that will go to 60m. Most of their housings are only rated for 40m. (the OP mentioned a dive to 175')
Their universal housing for RX100 series is rated to 60M, same as the one for A6xxx series - they're built along very similar lines. The big advantage of Fantasea housing over Meikon, in this case, is access to the rear dial of the camera, which the Meikon (as well as Sony's own housing) lacks - and since RX100 lacks any other dials, this can be considered significant, especially since Fantasea's price premium, in this case, is smaller than usual ($400 vs $256, compared, for example to $975 for Fantasea FA6500 to the same $256 for SeaFrogs A6xxx).