On maintaining sharpness: I have found .404 to hold up much better. Search YouTube for redbull661 .404…he tests it definitively.
I have some discontinued oregon dpx semi chisel 3/8” Multicut/Duracut which is triple chrome plated for longer stay sharp. Out of the box cutting performance seems slow, but it does seem to stay sharp. I am going to try putting some hook in it and see how that does. Maybe also modify the safety humps into chip sweepers - rakers.
Regarding chain speed : I believe slower speed will increase sharpness longevity - but here’s a funny thing. A .404” rim sprocket is the same diameter as an 8 pin 3/8” sprocket…so the chain speed of .404” would theoretically be faster than 3/8”-7pin.
I have found that the euc is so hard that it is hard to get a bite, and the chain can be a little more aggressive than i originally thought for hard wood…but if you get too aggressive, big chatter! Here is a sample of that:
Something I learned from
@rogue60 is not to get too aggressive with the rakers, and use the dogs to exert a little pressure to settle vibrations from the hard wood. Fast softwood cookie cutting method of sharpening aggressively and dropping the rakers and letting the saw pull down through the wood doesn’t work as well.
lastly, here is some factory Stihl square ground 3/8”. It shows promise for speed, smoothness, and stay sharp. Square is not supposed to stay sharp in dirty wood, but on the other hand the working corner is much more supported than on full chisel round filed. It can also be sharpened for speed or stay sharp angles.