The Arc Ultra is a tremendous performer vs the Arc.  Although the Arc was no slough. Everything is much more expanded especially for Dolby Atmos movies and music (both stereo and Dolby Atmos.)  Dialogue is greatly improved. 

My media room dimensions are 14 feet wide, 20 feet length with 8 foot ceiling. It consists of the Arc Ultra with dual Sub 4’s (both off center) one front on a parallel plane as the Arc Ultra ; which is 39 inches above floor and 26 inches from front wall. The other Sub 4 is 19 feet to the rear off center. Both subs are 5 inches from the wall (not in a corner).

Surrounds are Era 300’s 10 feet from the Arc Ultra and 56 inches apart on Sonos stands. They are 6 inches to rear of seating area on left and right. Yeah, they are somewhat close to seating area, but TruePlay adjusts for an immersive experience.

IMO a good movie that has plenty of different sound effects good low-end, dialogue and music to really push the Arc Ultra is Twisters on 4K UltraHD Disc (released July, 2024). Low-end effects were felt in my seating (leather theater recliners) which means everything was perfectly balanced for my room.  My disc player is a Panasonic DP-UB9000.

I’m a smooth jazz listener by choice. However, the soundtrack for Twisters is country music. If you’ve ever listened to good Ole’ US of A country music, you know that it’s an excellent genre to addition any speaker. Country music IMO has vocals and instruments ranging from strings, brass and percussion that truly test a speakers performance for clarity and overall sonics.

The bottom-line is that if you are considering upgrading from the Arc to Arc Ultra or a first tine buyer…I say go for it. Especially, if you are a movie enthusiast like me.  If a first time buyer Sonos offers a generous return window with free return shipping

Note: Room dimensions and topography will influence the performance of any soundbar be it Sonos or another brand.