The room extends back partially to door 26' 1"
The length of the room is what's giving you the success.
You've noticed that the business part of the panel starts quite a bit higher up on the 20.7s than it does on your old 3.6s.
You need more distance between yourself and the speaker to get it to sound right.
That's what defeated me, I couldn't get far back enough as my living room was too short and extending the house wasn't an option. I like speakers but not THAT much.
You're so right about them coming alive at lower volume, too. Someday I'll get another pair but not in this house.