When I run map compare to compare my stats with a friends, I'm looking to see what caches we haven't done. However there are ones they have done I haven't because they are my caches and vice versa ones they haven't done because they are their caches.
In the map compare could you exclude from the stats caches that were hidden by either cacher being compared. Or include an extra stats line.
So instead of:
20 caches only X has logged
24 caches only Y has logged
have perhaps something like:
15 caches only X has logged - they have logged 5 caches belonging to Y
12 caches only Y has logged - they have logged 12 caches belonging to X
Even better if it said "they have logged 5 caches belonging to Y (62% of Y's caches)".