McIntosh C27/C29 vs C26/C28 & MC2125 vs MC 2105

A question for McIntosh historians: I've owned a C27/MC 2125 since 1982, and for years abandoned them for trendier and really quite good alternatives (VTL, conrad-johnson, Musical Fidelity, etc etc) but recently went back to them and wondered about my sanity in ever having left. In fact I just added a second MC 2125, and upgraded the C27 to a C29. But in looking for used units, I noticed that the earlier generation (even-numbered preamps) are much more common, and MC 2105's must outnumber 2125's and 2155's by 10 to 1. Why is this? And is there a rational explanation for "The World's McIntosh Headquarters" valuing 2125's not only below 2105's but even their meter-less cousins the 2120's? Mind you, I'm very happy with a pair of 2125's driving Dunlavy SC-IV/A's -- I just wonder why the enthusiasm isn't shared.
You're right! I had a C-29 (and a C-28 and C-26) and sold them. I really like the C-29's phone section. Best I've heard. I went through many upgrades (so I thought) and have regretted selling the C-29, and the MC-2300 that went with it. I too have looked (still do from time to time) for another C-29 and either they didn't make many, or NO ONE is selling them. Excellent point. Oh, I ended up using vintage Harman Kardon Citaions pieces. A Citation 17 preamp and a Citation 16A amplifier. Love them both, but still miss the Mac's from time to time. Answers anyone?
Maybe since the 2105 has more of a historical value than the 2125? I found the 2125 to sound much better than the 2105 IMO.
If I may add my 2 cents worth, I have owned the MC2105 and just purchased the MC2125. Historically, the MC2105 & MC 2505 were one of the 1st SS amps with the blue meters and around 12 thousand of each of them were made. The MC2125 was made later and only 5 thousand or so were made. IMO the MC 2125 has a much better detailed sound and drives more bass than the MC2105.