A little more fragmented information.
I decided to do my initial cut test on brass.
The brass is a free machining alloy 360 brass, not leaded.
The round in 2.25 inches.
I used the popular eagle head clip art from Vectric.
Being that I have not yet cut brass on this machine I was VERY conservative with Depth of Cut and feedrate. I kept the spindle at 8,000 RPM.
I tried cutting dry, with WD40, and with Tapmagic. All are the same, no apparent performance difference.
First I faced the top with a 1/4 uncoated 2 flute end mill.
I was cutting at 25-30 IPM @ .012 DOC.
Second I used a 1/8 tapered ball uncoated to rough the dished eagle
Cutter from Burchette Tool. Feed 25-30 IPM DOC .032
Tool chattered a bit. I attribute that to length of tool.
I left .015 for the finish cutter
Third The tool in question
.5mm tapered ball from China.
The cutter is pretty stubby.
Started cutting at 25 IPM - quiet looks good
Increase to 50 IPM - same result
Increase to 75 IMP - same result.
I am confident I could have gone to 100, but I am uncertain the 3 axis motions would not have been good for the machine. I am pretty conservative and I don't like to push the limits.
A short Youtube of the tool cutting at 75 IPMhttps://youtu.be/C2eAAD_HU8E
My Opinion and summary
Price wise - You could not at this time use words to tell me that it is not work it. Even if I was operating a production shop where I depended on having cutters available I would still use these cutters. I would stock my shelves with cutters, to ensure availability.
Quality wise - I consider myself to be an expert in carbide cutters being that I do work with all of this stuff on an engineering level. I will deem these cutters to be on par with all but the top level most expensive cutters available. Even at that, not all that far below.
Performance wise - What more can I say. I just got done cutting brass at 75 IPM and the cutter didn't fail.
Reliability / Repeatability wise - I don't know, but based on these 5 cutters, visually, they all "look" the same and they all "look" good. They ARE CNC ground and the Chinese ARE learning to do better quality. I have a high level of confidence that they will be repeatable.
Summary - will I do it again - YES