Yeah, I definitely wouldn't trust any collar unless I was positively sure it could break away very easily. Until I modified his I just considered it a risk and made sure I watched him. The thread you posted is so sad.
I'm not surprised, though, and I'm sure there are even worse injuries out there caused by a seemingly harmless collar. I definitely wouldn't trust a collar not to get stuck, those things just seem to happen at the worst of times, and since I'm always watching him, it will probably never happen. Not that I would want it to, it just seems like they always seem to get stuck when you're not looking. :[ I think that as long as people are truly careful, though, there's nothing wrong with a collar. They can be dangerous, but there's no reason why every and any collar has to be. You've clearly been very particular about your collars and that has paid off, thankfully.
People seem to react very strongly to even seeing a collar on a cat, which I understand, because everyone is concerned about the safety of the cat. I just think it's kind of unfair that people make the blanket statement "collars are dangerous". Pain-killers are dangerous, cars are dangerous, almost anything can be dangerous if it's not used safely. I think that as long as you have a reliable breakaway collar, it's not a risk, just a benefit, because they have visible identification.