Rob, First off I am new to knapping too, and yep, it is definitely addicting. I spent 6 hours working on two points Saturday afternoon and never realized it.
As for the difference in Texas chert and Keokuk, I was told last fall that Texas chert is better for hunting points because it holds a sharper edge than Keokuk. I showed a guy the Keokuk points I had made for hunting, he kinda grunted, and said that I should put them in a case cause those will never be sharp enough to hunt with, and that I should get me some Texas chert. I did, and I must admit that the Texas chert does seem to have a sharper edge. But that is just a new knapper's opinion based on what I was told by an old knapper.
Best of luck with you points!
Neal