Lots of good info an opinions here.
As others already said, I really depends on your use case. Working on cars alot, yea, I use my 3/8" drive Koken's often enough to make them worth the money. Engine mounts, front drive accessories, timing gear, even light duty suspension work mostly.
I think Tool company's love to make money by selling things you "need", but I find them useful for what I do. They are not indispensable, but they are helpful.
Random, but does anyone think Tekton is on fire the last few years? 15 years ago I thought they made junk when I was new wrench looking to invest in a brand. Now, they are halfway between mid / top tier in my book.