@admiral You'd assume incorrectly, and you don't have to be a "player" to "create fun for those they interact with". You could be a metagaming fuckwad but if you still created fun you could be considered a "good player" under those criteria, also it's not another player's prerogative to create fun for others, it is a player's prerogative to create fun for themselves with the tools provided in the scene they find themselves in. There are so many different qualifications of a good player that stepping outside the bounds of the direct comparison between the subject and the qualification makes the whole argument mute.
Basically what it comes down to is from what I have found it is much much more enjoyable to not get sideswiped with sudden information. Of course things you are talking about, secrets, quirks, etc. That's all shit that is not normally going to be on a +sheet, that's normally going to be on a +bg or something similar. +sheets primarily only contain statstical information, which some might be spoilery (Allies: Mafia for instance) but they don't tend to give it all away and you can definately still slow release all you like and as my original point was, a GOOD player can go into a scene knowing all your dirty secrets but still react appropritely as if their character had not known these things because of course their character does not know these things until your character reveleas them.