15 years ago, during a dive on U2511 (off Malin Head, Ireland) after turning by the rudder I saw my dive buddy was far away recording a video, and I felt quite alone and paused to consider how effective my shutdown drills might be at 65m, and whether the gas I retained would be enough to reach my planned gas switch at 40m (a long swim away). I felt unsure... and resolved to get a CCR. My buddy was diving a CCR.
As soon as I got home I emailed my intended instructor and we arranged to do mod1 on the AP Inspiration, with a recreational trimix, rather than air diluent. The Inspiration was my choice as all the CCR divers I knew used the same unit so spares and mentoring options were better.
Two months later, having completed the course, I was offered the option of buying the CCR I'd used for the course. With modifications, that is the same unit I dive today, and I view the decision of switch to CCR as one of the best decisions I have made. I should have switched sooner!
People have raved about alternative CCR choices, which all do pretty much the same, except I have a temp-stick to visualise the state of the scrubber, and I find that reassuring.