I think it can depend!
In low level hi-Z applications like electric-guitar-to-amplifier, I have certainly heard the impact of different brands of cable very clearly. At line level, or in microphone-to-preamp sorts of applications, it becomes less clear to me (though I've done very little controlled comparison). In speaker applications I've also done very little intentional comparison, but I do know that we switched brands of speaker cable at our studio recently, and some normally-skeptical engineers with good ears claimed to perceive a difference (I was not there for the before-and-after... I can't swear that I would've even noticed the change if not told about it).
In either case, I tend not to fuss about it too much, even with instrument cables. I like Canare GS-6, and that's what I get when I make my own, but will use just about anything of reasonable quality that works if it happens to be nearby, and I can grab it without interrupting creative flow.