Lately at work my team has had a small habit of not swapping out enough … the same pairs would sit and work on a project from beginning to completion with little or no swapping. Luckily we started breaking away from this last week, and this week alone I swapped in on several different projects.
I have to say, I loved it! Getting to swap around more lets you get to see different parts of the system being developed, and I got to provide my expertise in some areas where the existing pair was having trouble, and at the same time saw a few tricks that improved my knowledge and opened a few doors in my thinking. Sometimes you overcomplicate something, and then you see someone just take the simplest approach, you just think to yourself “Why didn’t I see that before!?”. :
I would say that one of the most underrated principals of XP is pair swapping and shared ownership … I’ve been left with a very positive feeling at the end of this week being swap so much, and at the same time have the confidence in my team members to produce such excellent work. 
This was a big thing to learn. I still sometimes stay to long in one pair, but it is very important to remember that a pairing is not a marraige, as my colleagues are fond of saying. Tks for reporting these positive changes.
My team (about 25 feet from yours) used to have the same problem. Interestingly, it took a management directive to force some of our ‘old-school’ developers to accept the promiscuous pairing. Generally, I rebel against anything that I feel is ‘mandated’. But in this case, pairing is like Artichoke-Spinach dip – It sounds unappetizing, but once somebody forces you to try, everybody realizes that it’s pretty good.