I purchased one of the early 55/2.8's that made it to the stores in Los Angeles in 1980. It had a very light resistance in the focus action, and when fully extended to close focus and grabbed by the front end and mount end, the body of the lens could be flexed across the lens axis. I had never experienced a new Nikon Nikkor lens that felt that flimsy...and never have since. I sent it to the local Nikon service, and they switched it to a stiffer grease under warranty. It still felt flimsy, but less so.
I didn't have it long enough to see if the oil separated out of the grease. I feel confident that now there are types of grease now, 35 years later, that do not suffer from oil separation.
Optically, that lens seemed very good(remember we're talking shooting on Panatomic-X, Plus-X, Kodachrome 25, etc) but also the picture quality seemed different from my previous 55/3.5 "K" version.