Everyone has a "but". Let's pretend you were going to set me up for a date. You're talking to someone about me and you're like, "Phil's a really great guy, but ..."
"... he is really passive."
"... he doesn't show his feelings."
(I'm pretty sure I know the major answers for this, but I'm curious how other folks would tell it to someone else.)
Now you finish "Phil's a really great guy, but ..."