I was wondering how much power does everybody have in your own personal games?? Our GM basically makes us into mushrooms.. ie we sit in the dark and he feeds us feces. None of our characters are particularly powerful and none of have any idea about the illusion or the denizens of the many realms. Basically we stagger along dealing with human and sometimes nonhuman antagonists. We have never met with anything really huge.. well if we did it didn't reveal itself but after a few games we are starting to understand that certain "people" aren't what they seem. The way our Gm managed to do this was by not letting us read the Kult Books. He has actually forbade is from doing so, and so we know nothing, absolutely squat. I have to admit that sometimes it is frustrating but mostly it makes for a fun and exciting game as we thrash around desperately trying to save our skins.

Well, I handle it this way: every character gets what she deserves. If the characters are powerful, they get tasks that need all their resources to solve. It all depends upon the group I am working with. I also disallow my players to read the KULT background, because I know how hard it is to separate player knowledge and character knowledge.
Regarding your question about the poerniveau I am mastering at: One group plays in the top league. They already have contacts to various Archons and Death Angels. An ex-character of the group also has awakened. If there are fights, I use tougher creatures for them to fight.
The other group is playing the opposite. They do not have a strong position at all, and are having more existential problems. They players are very immature, and they prefer the 'hunt the artifact'-game style.

Its almost impossible for me to keep my players from knowing about the Kult Universe from the books -- I admire their tendencies to be sneaky bastards and to discretely inquire either from other Kult players or from hanging out on mailing lists like this one. "oh no, we never *read* the books"
Well, screw it. I don't like every direction the source books have taken anyway. So, I come up with my own stuff, using the basic framework provided, mostly geared so if people use knowledge they *know* from the books, they are screwed. Not to mention severe penalties for not playing in character.
Most of the time, I find my players are too easily distracted with little stuff to worry about them going after real knowledge. Every once in a while though, they surprise me, and I get to explain a little more about how my universe operates. Sometimes, I think it happens too rarely, but I don't like to goad players into on direction or another, but let them move as they will. Of course, there are those players who think they can just look for some scholar, or warlock or library and "find" such knowledge, but for the most part, they find misinterpretations and lies, or, worse yet, some piece of the guarded truth.

Anyway somebody asked about the power-level of different peoples' Kult-games. Personally I've ran one long campaign (took a year and a half to finish it) and currently I'm running another one, and in both of them all the specs I gave for the players when their created their characters were "16-25 years old unemployed, student, or worker". So in the first campaign the original cast included two ex-addicts and a schitzophrenic senior high school girl. After some time a fourth player joined the game, and her character was a religious senior high school girl. The best skill the whole bunch had was Football 15 on one of the addicts, he would've been a very good player if he had just continued his hobby.
None of the players of the first campaign, which I held in another city, had ever even heard about Kult, and they didn't even want to hear anything their characters didn't know.
In the current campaign there were additional specs for the characters, they had to have suffered from a mental or social problem for which they had been institutionalized. The game is centered to a social security project in which the characters are being rehabilitated to the society by giving them a collective house to live in. The idea is that they would support each other and so on. Currently we are playing the first year of their life in the house in sort of "fast-forward" fashion. There is an event or two in a month, I tell it to them and they react. Mostly the players just pick up the thread I give to them and start to weave a most complicated network of their social relations. It's fun just to lean back and let them play the everyday life of their characters. There's been some strange things since they moved to their house, but nothing very dramatic. The last session just before the Christmas was centered on the characters spending their first Christmas together. Almost all the session went by as they were buying Christmas presents and so forth, and the session ended in the Christmas eve when a present that was not bought by any of them and which they just found from under the Christmas tree caused them to have a "low on festive spirit -error".

One of these new players has read the Kult book and another one has played in a game where there was more supernatural effects than in this game (so far!). I just write up my scenarios in that way that it's absolutely of no use to know stuff about Kult background. Besides, I tend to choose my players carefully, and I must say that for example the group for which I'm currently running Kult is terrific.