I was reading some of the old threads about Cairo, and I gathered that you must choose between these two skills (i.e. you can only get one or the other). Is this correct? Do things work differently with these two faction skills, as in there is no going back once you've picked one. If this is the case, is there a consensus on which skill is more helpful?
I realize the answer may contain spoiler information...If it does, just PM the answer if possible.