The thing I don't like about the regular 306 drip tip is it puts your lips too close to the atty making it very hot. The cannons look like they allow you to put a little distance between your mouth and atty, which is why I've been looking at them. The pyrex, although they look nice, seem tapered in such a way that your lips would want to rest just above the atty. It seems to me that the heat from the atty would make this drip tip uncomfortable to vape with. I would be interested in hearing what those who have actually used the pyrex ones have to say about the heat issue.
I've been using the pyrex for over a month now, maybe two months, on 1.5 306 and I've never noticed much of any heat. I love the clear cannons, and all of the CherryVape DTs and have a sizable collection of them. But my new favorite 306 atty DT is the Pyrex. I love it so much I just got in a second one, backup, just in case I loose or break the first one. When you click them against your teeth they feel and sound like a "plastic."
One note on any 306 atty DT. I've ordered LR 306, from several places, for months now, IKV being my favorite. Two that I ordered, months back, are too small to hold any DT. And I don't remember where I got them. The only DTs that fit them are the DTs that came with them. I did find one clear Cannon, out of seven clear Cannons, that would at least not come off when I take a toke. There are variations in all 306 atty, even in the same run, but those two are drastically different in size. So if you have an atty that no DTs will fit on snuggly, most likely it is the fault of the atty and not the DT.
Alice