Many seem to be talking about their last system .

@bdp24 - yes, the quality of the media is ultimately important; as you so correctly say, the "limiting factor".

@inna - I appreciate your many salient points.

@brayeagle - thank you!

@three_easy_payments - "I'm unaware of any upside to dying with a prudently configured audio system." - In full agreement here.

Really enjoying this thread because it is quite relevant to me. 

In the end, it is all about the sound you like, and of course, can afford.

I have usually had a system for ten plus years. My outgoing system was around 12 years old and the prior was probably 20 years old. Recently I purchased what will likely be my last system (I'm maybe five years away from retirement). There will be some tweaks including wire and power conditioning and possibly a source upgrade if it can beat what I just purchased and be affordable. But I'd see the source as being a relatively distant upgrade.

I now have the distinct pleasure of owning the TAD Evolution system with E1 speakers (when I heard them I knew then and there if I could ever afford them, there were exactly what I wanted), TAD preamp/DAC, and stereo amp. The source is an Aurender N10. For me, this system just sings and it is all I've ever dreamt of. Deep but controlled and fleshed out bass, amazing midrange, and a very sweet, detailed, and non-fatiguing top end. The resolution of this system is very high and it never sounds veiled, with the right media of course -bdp24. With the right media, it is as if you are there. -Let me emphasize that system/component synergy is key to the highest quality sound. I bought what I bought after many demos with the E1s and different components.

I won't wax eloquent about the sound (mostly because I'm not adequately skilled in the audiophile vernacular) but will say that 'when you've heard it you know will it'. That's the way I feel about my new system. I've saved long and hard for decades and am blessed to have found this system and to have been financially able to make it happen.

I will say if you are in the SoCal area and in the search to build a system that sings, then please contact Mike Rose @ Excel Audio in Newport Beach. He understands system building and can put together a system that is highly synergizing. He is also, by far, the best dealer I've ever worked with. I am in no way financially affiliated with Excel Audio, I'm just a truly happy customer and blessed to know Mike (and to be able to call him my friend too.) When you meet Mike, you'll immediately understand his deep love for music and the music making apparatus. It is infectious and to me that is what this hobby is all about. Thank you very much Mike.

Thanks again to @inna for starting this thread.

One thing to be aware of is that buying and selling may not work very well because you may never have a complete system that truly synergizes together all at one time. "Endless upgrading" as the topic discusses, may not be an upgrade at all but a bunch of sideways moves. That is why when I bought my most recent system I bought from a dealer that had not only the ability to match gear well, but was more than happy to work with me until we found what made me not only feel, but know, what worked well together and made the sound I wanted; note in particular it was about the sound I wanted because we don't all want the same sound. I've spent the last five or six years going to shows and dealers and I knew when I heard the speakers that I bought, if there was any way I could afford them, I'd bring them home. I brought them home with electronics including a server source that just sing together. I do realize that not everybody has local dealers they can visit and so not everyone can take this route to design a system. But if you don't have local dealers, going to a show can get you pretty close or at least push you in the right direction. Forums like this can help too, but in the end it is about what YOU think sounds good and so taking someone's word for granted may not get you what you want. The proof is always in the listening and of course if you can hear a system in your own listening room that is even better yet.

One more comment. I'm maybe five years away from retirement and thought I'd purchase my last system after I'd crossed that line and had even more time to research and go hear equipment. But then I heard the speaker that wouldn't let me stop thinking about it. I'm glad I decided to make it happen now as who knows, hearing could be worse in five years, I could get killed on the way to the gas station, whatever. We all have different goals; I've been a pretty frugal guy all my life and this was my one bid splash out. It brings me joy everyday, even if just using it in conjunction with my TV.