Fat free does not taste the same as fatty. Fat free cream cheese in particular has a strange flavor to it. Like a soft bland cheese instead of a slightly sharper cheese. I can only think of it as a sort of anti-umami.
There are times when fat free is necessary. The issue is how to fix that bland flavor, to make the fat free cream cheese taste better. I tried salt, all sorts of spices and flavors that should have added the necessary bite. After lots of experimentation I finally hit on it.
To make fat free cream cheese have the correct level of umami sprinkle dried chives on top.