Update:
We replaced the old fluid in the 92 Pathfinder MT and put HyGard in a couple weeks ago.
Drained and refilled using the full hole on a flat surface first. Then drove it up on ramps on the passenger side to tilt it far enough to get a the full 5.1L (5.4qt) in. And that worked! For future reference we needed about 10 inches of lift on the passenger side and it was just right.
Similar to my little car, so far I'm impressed with HyGard. Much smoother on cold mornings (a few days in the mid 20s F) and most of the notchy feeling going into 2nd is gone. I've also noticed we can downshift into 1st while still rolling slowly, had to make a complete stop before. Again, it seems really smooth and *feels like it accelerates a little smoother or more freely. Overall a more pleasant driving/shifting experience.
With the old fluid (whatever it was), on cool mornings before moving, the idle would increase a fair amount when the clutch pedal was pushed in. That seemed to indicate a fair amount of resistance in the transmission when the clutch was engaged. Now I'm the same conditions the idle barely changes at all, almost imperceptibly.
So far so good. We'll see how it does as the weather warms up. Being this fluid is used in massive tractors under heavy loads in the heat of summer I tend to think we'll be ok but it's also an unconventional use. The Toyota is easier to service so I plan to drain the HyGard and take a close look this summer and I'll give another update here.