I just made the jump from a typical college dorm/bachelor pad system from the 1980's to a system that probably cost around $20k 10 years ago.
Of course there is a difference and it is not subtle. At the same time I do not find it life altering and I would never consider spending $20k on an audio system.....even as I get more and more into this hobby....which, in many ways and like many hobbies can get bat crap crazy real fast.
Just look at noromance's response, which is a nice, thoughtful and honest response. However, if someone is asking what the difference is between high and low end, they are very unlikely to have any notion of what things like speakers disappearing are, or improved colors for different instruments (when we don't know what an instruments's color is to begin with), or what congestion is.
We might can form an idea of what stage depth means and what detail entails. We might wonder why we want to hear a cough in the audience.
He also mentions minute changes to system easily heard. I've struggled with this. And that fact makes me feel like I just don't get it....until I come to audiophile forums and find people insulting each other's mothers over the merits of cable burn in or expensive power cables....all of whom have $20k+ systems.
Not knocking his response. I'm sure it is spot on for audiophiles but maybe not for those planning on being audiophiles.
And there is a whole language that you have to learn in order to discuss all this too. And even among the best audiophile writers it seems like the language and terms are inadequate....not that the critic or writer isn't competent but just that words often can't describe what they're hearing. And subsequently you hear a lot of those terms over and over again to describe various components and tweaks....which makes you wonder if they're real or worth the $1000 you just spent on speaker cables (like mine).
My advice as someone jumping in: don't overthink sound quality that you are happy with. Don't become unhappy with what you have because someone else says theirs is better or even worse because someone wants you to buy what they make. Remember, the economy, and especially the audiophile economy, runs on dissatisfaction. For me, I don't want or need another hobby that keeps me in a constant state of dissatisfaction and envy especially when that dissatisfaction is based on largely subjective observations and personal preference.
Having said all that, I am happy with how my system sounds, I find it intoxicating, I enjoy listening more and find myself finding more time in order to do it. And having said that, I can still listen to my 1980 Toshiba receiver driving 1990's Bose bookshelf speakers and really, deeply enjoy good music....and to be honest....still be amazed how good they sound!