It can be done, but of course you trim the airplane, not the forces, which is annoying and frustrating, in the beggining. It takes a little practice, then it is easy, but usually with a lot of unelegant pitch oscillations as you release the sidestick to check if the trim input was good or not.
I wonder if FS geeks would trim it better the 320 in direct law than real 320 pilots, since that is the way a FS airplane is trimmed. However I have seen how FS geeks crash a real 737 simulator because they couldn't trim.