I know this is a broad title but I'm thinking about the point with various components when you say 'enough', where improvements in frequency response, detail, sound stage, dynamic range, impact and other factors finally come close enough to your criteria for listening pleasure. I'm pretty much at that point with my system and don't see spending more as a solution that improves anything in a meaningful way. My turntable was a big step up in absence of rumble and a real sense of 'black' background over my previous Thorens TD160 Mk.II. The cartridge has all the detail and extension I could want without harshness. Music sounds more real than with my previous Stanton 681EEE-S. My CD player works well and sounded great using its internal DAC. Music isn't harsh or edgy unless the production made it that way. Sound is detailed without an etched quality. I had heard very slightly better with the MCD201 that I'd owned and wanted that additional increment of improvement again. My outboard DAC made enough difference that I'm happy with the CD sound, plus I can run my Blu-Ray, TV and other digital sources through it as well. My amplifier and preamp are as good as I can imagine using in a non-dedicated room. There's no harshness or softness, bass is well controlled and I can't imagine a realistic improvement that wouldn't cost at least $20K. It's not going to happen, even if I won a lottery. My speakers are easily driven, have lots of dynamics and extended tight bass. They are one of the least fatiguing speakers I've ever listened to but have tremendous detail. Any change would involve me having too much money and wanting 'the best'. I've listened extensively to pairs of speakers up to $150K and some of them quite frankly didn't sound as good as what I have in my livingroom. Interconnects and speaker wires I've got to the point where I'm unwilling to spend more despite hearing small improvements in overall sound quality when A-B testing with ICs that cost twice as much. I've halved the cost of ICs and maintained the same sound quality by making some of my own with OCC bulk cable and Eichmann Bullet Plugs. In my experience, speaker wires don't make a big difference unless there are factors that make the amp/speaker interface poorly matched or unstable. Neither my power amp or speakers fall into these categories. I'll continue to use my no longer available TDK OCC speaker cables probably forever. What are your thoughts on climbing the audio sonics ladder?