Raphr,
Thanks for posting the Cullen presentation - some good stuff!
I will try to briefly discuss you inquiry as to the prospectivity of these formations in the Permian Basin.
First off, deposition of these rocks in the Permian Basin area is differently in many ways from how it was deposited in the Oklahoma area. And the burial and thermal maturity story is also different - as is the tectonic (I.e. structural bending / folding / down warping /etc.) is different.
As to the Barnett, there has been some drilling focused on that formation in certain parts of the Permian Basin - mostly in the Delaware Basin area. This target is one of the focal points in parts of Apache's Alpine High area.
In other parts of the Permian, the Barnett member is either not present (non-deposition and/or erosion) or a "non shale".
As for the Mississippian, this was one of the major drilling targets in the Permian (especially in the Midland Basin and Central Basin Platform) for years prior to the emergence of the "Unconventional horizontal shale plays".
Success in this formation was tied normally to structure similar to other deep formations like the Ellenburger, Fusselman, Devonian, Silurian conventional targets. And variability in the geology / reservoir plays a big part in making the Mississippian successful.
There has been some horizontal drilling focus on the Mississippian over the past few years - the area that sticks most in mind as to this approach is in northern Borden County around Gail where some operators (e.g. SM Energy, Chesapeake) have done some horizontal drilling and stimulation. There are a couple of sweet spots in this area with good results but there are also areas of very dismal results - differences tied to various geological variations.
That's about it!