The Cheskys Al mentions are indeed great recordings and very well-made CDs. I think that while many of the analog recordings have been well-transferred to CD, many were not, particularly early on when the major labels started reissuing their old recordings in a rush to sell CDs of their old catalogs without taking much care in what they were doing (like using original masters, paying closer attention to the analog to digital conversion, etc.). Specialist companies like Chesky and Classic Records took the plunge on doing quality reissues of excellent recordings, and eventually major labels like RCA and, especially, Mercury, started to reissue their old catalogs with quality in mind.
I do find that many current all-digital classical recordings can be excellent as well, as digital recording has come a long way. However, I do think that certain instruments, solo piano, in particular, sound better on recordings that were originally analog recordings--to my ears the overtones and decay are better preserved, as the OP notes.
Just my two cents.