Tony at Starless River recently lent me a brand-new CT chest ascender to try out (how's that for service?!) - I've promised to try it on a clean rope indoors first! But he said if I like it, buy it, if not, hand it back. Superficially it looks like the old Croll, but is slightly heavier owing to a chunkier frame and a stainless release catch. Sadly no stainless wear plate, and the cam itself seems to be chrome, so back to the old problems in that department - but it's full-size and seems to be made for caving, as opposed to winning aesthetics awards.
Interestingly, watching cavers struggle to undo the new Croll during the Speleo-Olympics competition at Hidden Earth recently (on dry rope indoors under lights) only confirmed my suspicions - it's a badly-designed piece of kit that clearly hasn't undergone thorough field-testing, or we wouldn't all be discovering this now. I suspect many more complaints will arise now as folks begin to upgrade. Other comments made yesterday at my club about its regular slippage on muddy rope were also noted, as that's happened to me too.
I repeat though - I have no doubts about its strength, but I believe as its functional operation is now to some extent compromised by its poor design, then the risk of usage (likelihood of a hazard occurring) has gone up.
So far, I'm reasonably happy with Stops underground, despite my having to bin one due to the spring on the gate getting jammed up with grit, meaning the gate no longer opens fully, I so can't get it on and off the krab! Though I always use a braking krab, as the Stop should be used as per a Simple in operation - as in, 'full on', not braking with the handle. That wears out both the rope and the Stop bobbin on each other, which isn't good. But on anything less than 10mm rope, I find most Stops just don't 'stop'...