I’ve used the Clearaudio ring for almost 10 years now. It’s become 2nd nature; I don’t even think about using it. Yeah you have to be careful cueing up, but you should be careful anyways!! The CA ring works even with wide and low Koetsu stone bodies, but only JUST clears it for the 1st music grooves. Yes I’ve had it lightly "kiss" the outer edge of a Koetsu (no harm). Cartridges with "out there" cantilevers are no problem, obviously. Probably not for the squeamish, but there have been 0 ring-caused incidents here in 10 years.
The centering mechanism is machined to exactly fit Clearaudio platters, and it works wonderfully. Perfect centering is a cinch. If I didn’t have that, I might have abandoned ring use. Some of those other centering devices look AWFULLY inconvenient. I had a Merrill Heirloom (still have in a closet) and its ring didn’t even bother to come with any centering device - you just kinda eyeballed it. You’re just gonna have to try it to see if you can deal with that aspect.
My CA ring has accumulated several small dings on the thin inner lip. That’s the downside of a very thin inner part (the upside being allowing a Koetsu to clear it). I don’t even know how most of those dings appeared; it’s just fairly delicate and time will take its toll. Doesn’t affect the performance, though.
I love that I (mostly) don’t have to worry about warps anymore. A few records are so damaged in patches (heat damage?) they cannot be corrected by a ring; those go in a discard pile. I’ve encountered just a few of those over the years.
Anyways, summary - I love my ring! Also have a SOTA Nova V with a vacuum clamp that works great, but there’s just something more satisfying about (gently!) ka-thunking a big metal ring on the table for each side, and it looks cool too! The Clearaudio tables are quieter than the vacuum SOTA, too (probably has to do with the bearing as well).