Well, I almost always change the filter anyway. I just can't stand the idea that "some" oil, a half-quart or maybe a quart stays behind and doesn't get changed when you change the oil.
I'm far from a tribologist, so you might shoot my reasoning full of holes. I am an engineer...
If your OCI is 5K, then if you change the filter only every other time, some significant amount of your oil will be in there for 10K. Would not that portion of the oil, those oil molucules, be more apt to break down, to form acids or sludge?
For me, particles are not the issue. If you're going to change the oil, why not change ALL of the oil (as much as is possible)?