Rivieraranch,
I have had my Super Zen for about the same length of time as you. I have at least a couple hundred hours on mine and it seems to have settled in nicely. My CKC replaced a 12 year old Zen Select with no mods (no hazen grid mod).
I have been running my Oppo BDP-83SE player directly into the CKC and from there directly to my Klipsch RF-7's and Stereo HSU subwoofer setup. The subs are connected to the CKC via speaker level connection. Since I have stereo 15" subs any changes in the low frequency range are readily audible.
One thing I noticed was that the volume settings on my subs are now much lower with the CKC then compared to the Select while achieving the same perceived output. Bass with the CKC seems much cleaner as does the entire frequency range. Just seems like there is a lot more separation between bass, vocals and other instruments.
Some recordings where the bass sounded a little muddy at times with the Select are clean with the CKC. In the past I thought these were problems with specific recordings. Seems like the CKC just has more resolution and dynamics.
I have a SE84CSP preamp that I used on and off with my Select over the years. It gave the Select a bit more punch but I always thought it caused mid and upper clarity to suffer just a tad. This being the case I really did not consider using it with the CKC until I reviewed Steve's White Paper below.
PRE AMPLIFIERS - do they help or hurt the sound?
https://www.decware.com/paper50.htmMy impressions of the CSP with the Super Zen is completely different now that I have been playing the two together for a week. I have not found any negatives, in fact it seems to enhance everything just a tad. In particular it seems to help resolve the low end even further.
I'm not sure how your Z-stage compares to my CSP ?? but I am enjoying the CSP / CKC combo right now.