I've overnighted, three to be precise, at Petro. The Hotel Avacha or Hotel Pertopavlovsk, unless something's changed, which I doubt. Avacha is nearer to the harbor and downtown, if that matters. As it turns out, I stayed at the end of April, snowed every night, gloomy everyday; apparently the locals thought this very normal.
Wonderful scenery, what one could see of it. Google " Explore Kamchatka" website, run by a Yank who lives close to the airport.
GF