Happy to hear of your good results.
My success rate with cast iron with brazed inserts has been high too. Pretty much all brazed inserts russian/chinese orgining seem to work most of the time as long as they are on small shank. I have met some pretty big russian inserts that were like 20 mm square and really thick. They were practically impossible to sharpen to a keen edge. I was told that they are really good on positive angle and DOC over 5 mm....our roughing is industrial finishing. Only systematic problem I had with brazed "hobby" tools of indian origin, markings were good but they would crumble. Two sets of them.
Inserts can be very good too, but there are two problems:
1: Although pretty much all brazed carbide tooling works I have had less than 50% success rate with cheap inserts. Some claim that they had better luck, but for me it does not work out to buy cheap inserts. Some relatively cheap tool shanks work fine.
2: The whole insert business is a jungle. After you have found the correct insert geometry that you actually screw into tool shank you are into a treat. There are different grades of base material, coating, nose geometry, chip breakers and what not. And all that is really really important! Some inserts are optimised for certain task. Remove the hell out of the stainless unobtanium steel, pressurized air as coolant and tip life of 15 min on really rigid machine.
And insert + shank is pretty expensive down payment. You need to know what you are getting. Then it works fine. THis is contary to brazed carbide...you buy wrong or dud and you loose 8 USD. Big deal. Usefull insert shank costs 20-60€ + box of inserts starts at 40 €....it is great when it works, but my income does not allow repeated mistakes.
And then there is skewed scale of how different machines we have. You just can't assume that hobby roughing is industry finishing. True to a certain extent but not exactly. Industry might be able to use much smaller tip radius, because their machine is more rigid, controlled materials and coolants. Hobbyist may need to compromise on pretty much everything else but time. We can't and we don't need to shift 3 kg of swarf in few minutes but some inserts are designed to do that.
Pretty much what I know is that for aluminium you need uncoated and "polished" inserts, some of them work for stainless steel and free cutting steel too. For most iron material I use "general" use insert that is PVD coated. And I stick with them. There are so many insert/shank/grade/chipbreaker combinations that you can get lost to them.
Confession time: I have some GRP500 cast ends...that is pretty high tensile spherical cast iron. I use PVD coated general use inserts after I get under the skin.
https://online.lamina-tech.ch/catalog?item=T0001889There are shitload of fake inserts floating on the usual sites. I buy these only from the local industrial tool distributor that makes me jump trough hoops to buy them, but original works for me. I have seen copies and they are hard to recocnize by looks, but all effort is used for looks, not for function.