Thanks Vondo.. was reading your report religiously but wondered if there was feedback about the other dive ops in Phi Phi eg Hippo Divers.
For what it's worth, I did my open water, advanced, and spent about a week after doing fun dives with Hippo Divers on Phi Phi, and they were absolutely brilliant! I dived with several other operators in my time in Thailand (not on Phi Phi), and none made me feel as safe, confident and welcome as Hippo Divers.
That said, from chatting to people I met out there I think in general the standard of operators on Phi Phi is pretty high, and does not vary so much as on Tao for example, where some are pretty shocking. I've heard good comments on Phi Phi Scuba in particular.