The step drills are typical China-direct quality; much better than some of the case-hardened cheese drills I've bought at Horror Fraught for sure.
A tip for everybody with regards to buying tooling from our friends in the Middle Kingdom:
Buy carbide tooling. I've never had a single piece of tungsten carbide tooling from China that hasn't been of proper quality, most have been first rate. The reasons are probably obvious. You can make something out of case hardened cheese with pretty much any other tooling
but if you're working carbide you have no option but to have proper tooling to do the work with. Carbide is so very hard that you're pretty much obligated to use diamond tooling to cut it, and while quite tough, isn't so tough that you can just "have at it" with the first machine that comes to hand, it requires a certain degree of finesse to work and not have it shatter into tiny pieces.
The recommendation to buy carbide comes however with a caveat. You have to understand how to use carbide tooling. Cutting speeds are generally higher and it is less tolerant of poor technique than HSS tooling. When drilling a soft, seemly harmless bit of aluminium with a carbide bit it's quite easy to snap the bit off if you go in with too few RPMs, too slow a feed rate, and skip the cutting fluid.