You know... it's funny you mention this issue... It comes up now and again but, recently, I've been thinking about it a lot. My wife is really tired of my 'hobby' and would like to know when I'll be 'done'. I soon realized I've been on this journey almost my entire life. When indeed, will it be good enough?
Here's where I got my answers:
What is my goal?
Is it 'the hunt'? Trying to find a better way to search for hifi ... getting better deals for gear.....
Or is it a better listening experience because I like certain music?
When will I know I've reached my goals?
My goal is musical reproduction with a little bit of 'deal getting' added in.
However, I have found:
Once you get a system to where you're really happy with it (in my case SQ and the deal I got), that should be it. Right? Wrong. 2-6 months roll by and all of a sudden you learn about these new 'Widgets' that tweak your system or the X12 Amp... and the way they're described creates awareness of issues you think you may have. "I didn't know I had a grainy midrange... maybe this new FET will be a better amp".... So, even if you don't have a problem with your system, you will find out that you could. Plus, I can get this great deal on the FET.
I'm an anal perfectionist but, not overly compulsive about it. I know that one day, I will have a system as perfect as I can get. In fact, my system is currently perfect. (especially after a visit from Kris at 8th Nerve.... see my post under their forum) I can't hear any mistakes that need to be addressed.
So, why am I buying new cables? Because I know it can sound even better. Kris at 8th Nerve confirmed new cables would help. Why would I limit my system by using this inferior cable? It's like, I've got the equipment but I'm not letting it get to my speakers... oh no!
OK, I'm getting too dramatic but, you get my point. Your system satisifies you now but, you're already talking about adding components. What happens when you get a turntable? A new sub-category hobby is formed... 'vinyl'.... good luck with ever being 'finished'. I thought I would be by now.....