This is one of the most well-informed opinions on the Web and in Spanish about pair programming subject. Well done:
Pair Programming: Qué es, Lo Bueno, Lo Malo y Buenas Prácticas
A note about the point 1 in section “the bad”, of course you know, “your mileage may vary” each project have its own particularities and over generalizations usually mislead and fail to spot the point, in this case point 1 seems to imply that pair programming is costly, but accordingly to the work by Laurie Williams on other projects with more experienced team members, the cost in fact decreased because of a continual practice of pair programming.
It seems to me that a customer aware of software design nature and its costs, will hire personnel with the attributes Armando lists on the section ‘Good practices’.