2006 Infiniti M45 151k miles
Drained 4 qts unknown fluid (maybe factory original? No records from previous owners)
replaced with 4 qts Nissan Matic-S ATF
Since the fluid I bought came in a pack of 5 qts, we drove 10 miles (noticed MUCH smoother shifts!), got back, checked the fluid level was perfect, then I pumped another qt out of the dipstick charging pipe and added the 5th qt of new fluid.
This was a much easier job than I anticipated, so we'll do it again in another year or less. The fluid is expensive, so it's not reasonable for me to buy multiple flushes at once. But I can do it spread out over time, which is the path I'll take.