I have a pile of unused subwoofers. I just hate them. I wish I didn't but that's the way of it. Foolishly, I buy some now and then, the last pair of PSBs are totally covered in dust in a pile about to be sent to the storeroom...
I've never heard a single 2 channel system, regardless of price, expertise in so-called setup/integration, or pedigree, where the subwoofers didn't just betray themselves, but they also ruined the stereo experience.
Even putting subwoofers under the mains or right next to them, just doesn't work for me. Other people, I dunno. Great for HT where the soundtrack is just there for effects and fun.