I have tested both vehicles (identically
equipped), both for week-long periods.
Curiously (and consider these are test
vehicles), I found the Mercury higher
in build quality than the Nissan.

Either choice is good, but beware that
I did not experience reasonable mileage
with the V6.  Average city driving was
<15mpg, with about 21 avg. on the highway.

Both were optioned to the hilt (the Nissan
had leather!).  The Villager was in the
$24K range and the Nissan was over $26K.