My setup is simple. And, I tend to be brand loyal. I usually only upgrade with Audeze, Chord, Kimber, etc. And, as I get the itch for the next shiny thing, something I have now must go. First, because that's how I can finance what I want, and secondly, because my OCD doesn't allow other items to be kept.
I can say that everything that I added to my setup made a difference, especially because I didn't do it all at once. Some items made a big impact, and some were more subtle, of course. For example, when I replaced the stock cables on the M Scaler with Kimber, it was actually a fairly huge difference. Next, I went away from my MacBook Pro as a source to the SOtM streaming setup, along with a Kimber USB cable, which made a noticeable improvement as well. This surprised me because I was using a nice USB cable already, but leaving the Mac was a big deal. Even the iFi Lan Silencer made a subtle improvement, I think.
On my LCD-5, replacing the stock cables with Kimber's AXIOS Hybrid brought a sense of control to the overall sound.
The very last thing I have done as of right now, and big thanks to
@EMINENT, was going for Mitch Barnett's Convolution filter for the LCD-5. His comments made it sound like a must, and it is!
I basically didn't know what I was doing, and I kept making my LCD-5 sound brighter and brighter with EQ, because I didn't know how to bring balance to it. But, after getting Mitch's filter, it has been like a dream. I don't even think about EQ anymore, because everything sounds so well-balanced. There is depth and a delicate tonal balance to just about everything I listen to, which I didn't know that I was missing.