I pair 100 percent of the day so 8 hours a day for the last year. It has been a very rewarding process. As a natural introvert pairing has made me a much more communicative person and my programming ability has significantly leveled up as well.
We pair with 2 monitors, 2 keyboards, and 2 mice facing each other with our own desks which I feel gives each person in the pair enough privacy and space to make us both very comfortable.
Is pairing intense? Yep. Is it worth it? Absolutely in my mind. The high quality of the code and the productivity is well worth it.