In your opinion what company makes the best brass?
I've used mainly Remington and Federal. I think Norma brass is probably pretty good too.
Does any one brand seem to last longer than any other?
I once read an article in a reloading publication where the author took many brand of new cases(all same caliber) and loaded them shot them, full lenght resized them and reloaded them again. He would do that until he could see positive signs of imminent case head seperation. The Norma's lasted way longer than all the rest.
That is not the most important aspect that I consider when choosing brass to reload. Aldough I realy like to reload and go to the range and test my load, I have a limited amount of time that I can allocate to these activities. So prepping a bunch of new brass in order to be able to segregate the good and the not so good brass isn't an option for me. I buy a bunch of Norma brass and load.
This is not blind trust. Belive me, I have several gages to take many different measurments on brass and have checked out quite a large quantity of Norma brass. On average 5% had minor flaws. Never had to send one to my recycling box. Now I only check for dented necks and repair those that are dented.