EDIT: Contrary to this contrary belief, it seems that all production models of the Sphynx and Gorgon are indeed air-pressure based and that the items I got my hands on were pre-production samples.
EDIT 2: Contrary to the contrary belief, it was brought to my attention (Thanks, cantab!) that these models were actually available last summer in the UK as Hydro Power versions. I suppose that is where the samples I got came from; old stock before the injunction. Will be pushing up reviews of the Hydro Power versions as well as the air pressure versions once I can get my hands on those as well.
