I use Tap & Die almost exclusively, and have done for many years.
Their HQS are carbon, but of fantastic quality, especially when cutting stainless, ground to razor sharpness and on perfect size, I have yet to have one break or go blunt in the dozen or so sets I have.
OK, they are rather expensive, but if you are after sets that last you a lifetime, they are the ones to go for.
A few years ago I was doing a long production run in EN1A, and thought to save wear on my T&D ones, I bought a set of 32tpi ME from Tracy tools. They may as well have been knives and forks, every tap and die was from a different manufacturer and not one cut to correct size, mainly oversize on the taps. I managed to give them away to a beginner just so he could practice with them. I ended up using my T&D set and every one cut tio size with no losses at all.
I think they are manufactured in India.
John