I've got a mix of different manufacturers dies, Lee, RCBS, Bair, Hollywood, Hornady, Pacific and even some old Herters.
Years ago, Lee might have let a higher percentage of defective dies slip past QC, but even then they'd always make things right, quickly and painlessly. I think Lee has improved their QC a lot in the last few years and I haven't gotten a bad product from them in more than a decade.
I did have a problem once when trying to load some ammo for an old CZ52 with a set of Lee 7.62x25 Tok dies. The problem stemmed from the gun, not the dies. This particular pistol had a .312 bore and the expander furnished with the die set wouldn't open up the case mouths enough to start a bullet.
I called Lee's CS line and after listening to me for a moment the woman who'd answered asked if I could hold for a moment. The next thing I heard was "Hi, this is Dick Lee, now what's your problem?" I told him and after thinking for a few seconds he said "An expander for a .303 British should fix you right up."
I asked if I could pay for it over the phone and he declined to accept any payment. Three days later I had the new expander.
Yeah, I like Lee.