Usually the scifi stuff was criticized a lot for never being as good as the fantasy stuff and never quite translating all that well to the FF system.
I’d have to agree for the most part. Though I dunno if was the system so much as it was the writing for most of them. One of the worst books I thought was Rings of Kether. (Most say Space Assassin, but I didn’t really mind that one as much)
In general whenever the FF series stepped outside the fantasy realm there was always more risk. I thought House of Hell/Hades and Freeway Fighter were okay though.