I am going to tip a bucket of cold water on this unit. The fact is that it is a lot of money for something that is not much use. The F3 is very high as you would expect, and then you drive hard it below Fs and its native F3 and get what you would expect, a bucket load of distortion.
The physics is all against you, if you are going to place a sub in standard existing wall spacing.
Since we are talking a lot of money, you should consider some stud, drywall and paint instead. That is not that expensive, all these products I mentioned are cheap, so the cost is labor which you can eliminate with DIY.
So, I think it is the depth of the sub that is important. TL designs are ideal for this and you can get the most accurate bass around.
The other issue is that it allows you to get the electronics off the floor space.
I know which sub I would rather have and listen to.
Crossover set to 80 Hz.