I've only ever used Remington brass in my STW, because that was what was available when I first got it, so it is always what I have stuck with. Not like I can get other brass much, if any cheaper, and it does good for accuracy. I've never noticed a lot of difference in accuracy between brass, but in my more accuracy dependent rifles (I never bothered in the 45/70 or Mini 14) I try not to mix and match brass.
I did notice with my 44 magnum pistol loads that some brands of brass weighed enough grains different than others that I couldn't tell which rounds were loaded without powder by weighing the loaded rounds, unless I looked at the headstamp. One brand actually weighed more without powder than another brand did with powder. (I don't remember which brand was which, but I Federal, Winchester, Remington, and probably a few odds and sods, and each brand had a different average weight, some brands significantly different). I couldn't tell any accuracy difference through a four inch barreled pistol, but always assumed such a significant difference might make a noticeable point of impact difference in a long range rifle; so I simply always avoided it.