The 20/20s used a different dome tweeter, updated midrange drivers and different woofers. Actually all 3 on the 20/20 differ from each other. The upper 12 on the front is a transition driver between the lower 12s and the midranges. The house sound is similar, but IMO better with the 20/20. I can’t tell you if the difference would be worth it to you or not.
Legacy Focus 20 20 speakers
What is the difference between the original Legacy Focus, and the Focus 20 20's Does it pay for me to spend $2000 on the 20 20's to replace my original Focus speakers?