Cancelling Qobux is straightforward - go to the Qi=obuz website for your country. Click on your username top-right, select my account and you will get options to Change Plan, Update Your Payment Method and Cancel - the latter is even in red text.
The only downside is that, as others have said, your subscription will continue to the end of your payment month if you pay monthly or the end of your payment year if you pay annually (i.e. no refunds on subscriptions that you committed to).
As for searching sometimes Qobuz can be a bit clunky, but then so can Tidal and Deezer (I have had both), but certainly not so much as Amax=zon Music (which I have also had). Spotify seems to be the only one that gets that right.
The only dropouts I have ever had were when trying to play 192kHz material in the car when lost mobile (cell) signal. This is, of course, purely a function of the signal that you supply to Qobuz!
Quality - on my system the sound quality is excellent (Moon MIND 2 into a Moon 650D CDAC/CD Transport, Moon 700i and Sonus Faber Concertos, all cables are Nordost), certainly up there with CD replay for 44kHz material and for higher resolution material there seems to be that extra bit of magic. In the car, I would struggle to tell the difference from any other service.
I found Qobuz much improved from all points of view including sound quality over both Tidal (especially the lack of French R&B suggestions), Deezer and as for Amazon ;-(