Then there is the removal of code review meetings/gate keeping. Little to no team silos and higher team redundancy. Faster team member ramp up. Lastly, higher code quality.
I'm not so sure that pair-written code should be exempt from code reviews. The two people who wrote the code made a bunch of decisions in the heat of the moment (and possibly under time pressure), and both are emotionally invested in the code that they wrote. If it's reviewed later by people who weren't involved in writing the code, it's likely that they'll notice problems that the original programmers did not, or see better ways of doing things.