I kind of like the idea on a "gamist" level, and they did what they were supposed to do in play - quite regulary, the players came up with some smart and/or entertaining way to use them. But they also felt very rules-first, in the sense of: "We don't care where it came from or why it does what it does, it's just a fun effect!" Which is legitimate, but in the long run, I don't like it. If there's lots of weirdness in the setting, I kind of want to feel that it flows from somwhere, that there's still a kind of overarching idea behind it beyond "Dude, it's been 9 Billion years, there's all kinds of crazy stuff!" Otherwise, it just seizes to matter as something weird to explore and becomes a game effect.
(That's another beef I have with Numenera, but it's really not about the rules: It keeps stating that it is about "exploration", but - at least in the early books, I don't own anything beyond the Into the Deep/Night/Outside trilogy - there really was nothing to explore, no connections to be made; it was just all "look, another crazy monster/weird artifact/giant hovering structure", without any connective tissue, so I had to come up with all the background stuff myself).