As I mentioned on your previous thread, I owned the 1200R which was the predecessor to the Ultra. I assume that the Ultra will be better still, and it has an even more powerful amp (1200W vs 1000W). The 1200R is still available at a saving over the Ultra.
There is no doubt in my mind that it will give a substantial improvement. I had mine in a room that was about 16 x 22 x 11 and it could move enough air so that you could feel explosions in the chest. Due to the EQ system, it could be bunged wherever it suited....I had mine in a corner without problem. The bass was deep, tight, powerful and played tunes. IMO It was better than the Rel Storm 5, which was its main competition at the time.
When compared to a relatively cheap Kef sub, it made it sound like someone hitting an empty cardboard box with a stick!
Now saying all that, only you can decide if the gain is worth the money (it was to me). The money could be put elsewhere in the system; or saved by getting a smaller diameter (800/1000 ultra or the Paradigm Seismic 110, which is a real rottweiler of a little sub).
IMO. For action movies etc. it's hard to look past a really good sub.