I have 4 of the Aura 50w in my sectional. They are amazing! They honestly add life to everything - movies blow up stuff better, music is way more immersive (and I have a pretty decent bass setup without them - an SVS 3000 and some big towers).
The only caveat is that you need good/easy control over them - when set where I like them at med volumes, they are way too much at higher volumes. Fortunately the Denon 3600 I got this spring has dual subwoofer controls.
I was worried that 1) the couch would rattle (it's a recliner with a lot of metal arms, etc) and 2) that they wouldn't really be noticeable or effective. Both were unfounded.
Honestly get them - $400ish all in for 4 shakers and a plate amp and it's awesome. Everyone comments on how cool they are.