Exactly! AFAIK, the AR-1 has roughly the same thrust as a BE-4 so ULA would need 2 to replace the single RD-180. AJR is trying to save their butts. I'm not confident they wouldn't overcharge for...
These seats probably wouldn't work for, say, AA with their ridiculous boarding procedures. However, a Frontier or Spirit with assigned seating may benefit by strictly controlling the boarding...
You lose it in shoulder/head room on the window seats though.
I would be disappointed. The 737 is more comfortable than A320s because it does not have a circular cross-section on the fuselage.
737 feels more comfortable because the widest part of the fuselage is shoulder level. A circular tube, like the Airbus, puts the widest part of the fuselage at hip-level.