Excellent write up
. I responded earlier but deleted my original post as it sounded too much like a PSA fanboy which wasn't intentional.
I took away several things from your post that you seldom hear on the forums.
1. "Too Much" really does exist.
While the 2400 ULF is the biggest, most expensive, highest performing sub in your audition, the way it interacts with your particular room resulted in it not being your favorite choice. Having too much output can have a negative impact on the sound quality in a particular room.
2. Bigger and more expensive subs don't always translate to being better in a particular room, but size does matter with ported subs.
3. If you hadn't experienced what you were missing with the V1801s, you could likely have continued to be happy with your previous setup. Sometimes ignorance is bliss and a big money saver.
4. The fact that you are in a smallish sealed room and on a suspended floor plays a huge role in the performance you can get from a subwoofer. I think the suspended floor is one of the most overlooked factors in achieving ULF bliss. It is impossible to get a thick concrete slab to transfer that ULF energy like a suspended floor.
5. Sealed subwoofers can be excellent performers but do require more power to achieve similar output levels to ported subs which can be a problem if you don't have sufficient electrical service in the room.
Thanks again for taking the time to provide your impressions. It sounds like Rhythmic may have a real contender for the best all around home theater subwoofer with the FV18 paper cone. Anyone that has the space for a larger subwoofer and the budget should have it near the top of their list.