I think this is the big thing for me. David Pogue, when he went on a dive with them last year, pointed out that the vessel has no beacon [1]; yet the door bolts from the outside. Apparently there was a five-hour period where the company did not know the location of the sub after it resurfaced.
To me, that seems crazy. Having a GPS beacon seems like a no-brainer for safety purposes. It feels indicative of the engineering as a whole.