This is my studio room. Double clouds, full reflections covered. Built most of the panels myself with Mike Major at gik acoustics doing a 3D mockup of my room before I built it and filling in with diffusion absorption Alpha 6A panels and scattering panels. I’m right at about +/-3 db from the listening position from 20 hz to 20 khz (besides a bass boost I added of about 6 DB as I mostly mix electronic, pop and hip hop stuff and need to feel that low end) with minimal EQ. RT60 and waterfall look amazing.
I’m considering treating my living room right now. It’s a fairly large open floor plan with 9’ ceilings. Sounds good right now but going to be doing some 6" or 7" panels for first reflections on the sides and pending WAF, a cloud or two for the ceiling.
The floor can be carpeted or hard. If the other reflection points are treated, I’ve heard it doesn’t really matter much. Over damping is a huge issue. I went with carpeted floors because that’s what I like. I do recommend doing a rug if you are missing your first reflections. It definitely helps to control excess treble ringing but pales in comparison to a fully treated room!