Hello, welcome.
I would avoid the B&W subs.
Look at the SVS, Monoprice Monolith (if available to you), and XTZ Subs.
Here in the US, at least with SVS customer service and their free shipping, and the fact they started off building subwoofers only, They are the real deal.
I have no experience with their phone app, but do not think that you would need to worry about it being obsolete. IIRC, all of those controls are also built into the Sub as well.
Regarding Subs with DSP, and use with Audyssey, it is worthwhile. Whether the DSP allows you to just tune a few settings or fully customize several aspects of performance, they both still work together to help you achieve the performance you want in your room.
That said, good subwoofers are amazing beasts. Good clean bass without distortions is a different thing from a sub that isn’t meeting those performance requirements. In fact, when set up properly, you shouldn’t even know that box is doing anything.
Hope that helps!
Cheers!