I bought a loop of picco duro lately. It might not ever need sharpening the teeth could chip. There is not too much length of tooth before the shape changes. I have not examined any rapid duro. It has not dulled noticeably on the battery saw but when I tried it with a gasoline saw two teeth chipped to the extent more than half the useable length was damaged. Some frost was involved, perhaps I hit the end of another piece of firewood instead of the side. Good luck with it. You can read the advice in this thread not to get it too hot. It works acceptable for cross cut or bucking and is pretty dismal for noodling. I have not yet really tried it in a limbing application. It would seem another section to replace cutters from would be something needed to actually wear out a loop.
thinking back .. circular saw blades i use on my table saw that are tungsten tipped.. do dull after a while, i cut up hard timber from demolished houses, a demolisher dumps off truck loads when i require it for nothing, saves him paying for tip fees, it's my main source of firewood
i like to be able to sharpen these blades myself, been looking at youtube videos
so i guess it would apply to tungsten chainsaw blades too, can't remember how long it would last untill it dulled [2 - 3 winters ?!]
anyway, i bought this property about 15 yrs ago, 1/2 acre - loaded with nuisance trees, so i bought my first chainsaw - a sweet husky 359 that hardly did any work for only 300 bucks, then once i thought i didn't need it any more i swapped it plus cash my way for a sweet 338 XPT
because i figured i just needed that to up-keep the remaining trees & it's been a good all rounder. stoopid move really.. coz now i got about 4 more that needs to die, shoulda kept the 359 and bought any ol' small top handle.
there's a tree root that lifted a concrete section in my garage preventing me from locking the roller door. thought about using the tungsten blade to hack it up. but after reading the thread.. think i'll just lift the damaged concrete ..dig around the root, remove as much soil as i can and use an old 12" chain for the husky