Decided to do another drain and fill last night and added about 3.3 quarts. The Wife noticed a distinctive shudder/rumble when idling this morning though (confirmed by me - 2 seconds off, 1 second rumble...etc). It was only while in D (not N or 2 or 1 or R or P) and seemed to lessen once the van warmed up.
So I checked my fluid as per the van's manual (warmed up, level, van off) and it was showing as low so I ended up adding another 1/2 (or more?) quarts in there to get the level midway between the dots, or so.
This seems like well over the suggested 3.3 quarts I've read elsewhere. BUT, my transmission was replaced by the previous owner...so maybe it's a bit different?
PS - I decided to go with Valvoline Max Life this time around after reading good things from many other Ody owners.