2003 3.0i with 70K. First time flush and fill for the diffs. Drained fluid looked good as new. Hardly even discolored..used Mobil 1 75w90 for the refill.
The transfer case was another story....fluid was black and very thin. Refilled with Amsoil ATF. Basically the diffs really didn't need the flush, but I'm sure glad I did the transfer case. I would definitely recommend a flush/fill at 30K for the trans case from what I saw...and especially since it's a 5 minute job and only takes 1/2 qt. of ATF.

..bob