I've been practicing doing this changes, from Am chord to F barre chord, I can play the F barre chord alright, got them 6 strings ring out clearly, but the thing is it's so hard for me to even hit 25 changes under 60bpm in one minute. I tried slowing down, and watch how my fingers move, when I switched from Am to F barre chord, I've found out that it was easier to put the shape down first rather than the barre, but still when I experimented using both ways, it is still the same. I can only hit around 20 or 21 in one minute.
I don't know is it because of my bad habits, or I'm not patient enough.