I had MK double stars until last week. Typically they were good for about 15 hours of skating, with hand stoning touch ups every 3 to 4 hrs. Way too soft edge material.
Bought a set of used Jackson freestyle EXT ultras. They are black anodized. Initial testing of them unmounted and comparing them to the dismounted Double Stars shows the Ultra to be much harder metal. Had them sharpened, the sharpening guy agreed they are much better tempered than the double stars, thus will stay sharp much longer. The Sharpening process is a good indicator of metal hardness.
Compared the Ultra EXTs to an instructor's Gold Seals, the EXTs appear to be roughly equal if not better tempered. Though the Gold Seals do look nicer. This particular instructor has hers sharpened every 40 skating hours, rain or shine. She keeps meticulous records of on-ice time. Shed had them for many years.
As a base line, low end skates will hold edges for about 15-20 hours, high end looks like about 40 to 45 hours, assuming not much skating on hockey ice.
PS. While I'm new to Ice skating, have spent a lifetime around metal, mechanical and other trades. I can tell good steel from scrap metal, regardless of what shiny coating it has, easily.