These last me about 15 hours each, consistently, on Alto Sax, Yamaha 4C.
My teeth aren't sharp but I do end up biting a bit when my lip gets tired or when trying to learn new altissimo notes.
The key thing is these guards are very black. This probably means there's more carbon in the rubber, which makes it harder (not the same as more vulcanised). The extra carbon makes these durable, which is why they're black and why car tyres are black. As a bonus it makes the rubber cheaper to manufacture.
These last much longer than greyish pads by Kolbl, As, or the clear Thomann pads, all of which I bit through in under 2 hours.
I haven't yet tried the BG pads or Yamaha's rubber, but I don't expect anything as good from them.
Removing the patch when it's done is easy. I've never had one delaminate in use or come loose, I just always bite through - but without marking the mouthpiece.
Easy to apply, I find the 0.8mm good for damping some vibration. I tried the 0.4 and found the vibration transmitted into my teeth painful after 30 minutes. So I'd recommend the 0.8mm.
Hopefully you bite less than me but this should give you an indication on durability. Try to get the blackest pads you can find.
