If I remember correctly…
You shouldn't see much difference. RAM will help you keep more applications running without swapping information to disk (which is the slow down) or keep in memory a bigger file for the same reason.
So if you just restarted the machine it will be as fast as it used to be with 2GB, while working you will not hear the hard disk spinning as much and applications might keep launch as fast as the first one since the system has enough RAM to not need to use the swap file.
Eduardo Rolón AIA NCARB AC27 US/INT -> AC08
Macbook Pro M1 Max 64GB ram, OS X 10.XX latest another Moderator