So, as I mentioned yesterday, I will be brewing up some new 4e flaw rules so that i can get some more feats for my players and for myself... hehehe.
I think we can all agree that the 3rd Edition Flaw rules allowed for some serious overloading of flaws in order to max out the number of feats you could take. Unless as a DM you limit the number of flaws a character can take, this process can allow some characters to get really broken.
My House Rule for flaws going forward is this:
Every time you take a flaw in order to gain a feat, the number of flaws required to get a new feat goes up by one. So, your first flaw gets you 1 feat, but to get a second feat, you have to take 3 flaws. It simply keeps getting worse and worse from there. If you are going to try to really optimize a character through the flaw trading process is going to get brutal fairly quickly.