I'd agree the hydride cannisters look a tad small compared to the energy storage claims, but I'm not exactly familiar with the energy density of that sort if thing. I know the brunton hydrogen powerbank seemed to be about equivalent to lithium ion in terms of H2 can size vs what I'd expect from an equivalent battery. Removable for household use seems a bit of a stretch. Its not outrageous enough to be utter bullshit, but still gives me "hmm not sure about that, I wouldn't adopt it first" feeling.
Membrane life and replacement cost, along with how much other consumables cost is also a big factor. I'm assuming there HAS to be an ion exchange resin filter to provide DI water to the electrolyser.