I can't speak to the C-22, but I have been happily using a C220 for about 6 years. Many Mac preamp owners have had good results from upgrading the tubes. I replaced the stock tubes with Mullard reissues (~$40 per pair), and got smoother sound, lower noise, and an expanded soudstage. And I absolutely love the functionality of my C220, which is not as extensive as the C-22. I would guess you will enoy your purchase a great deal.
New Mcintosh C-22
At the place of purchasing a new C-22. Will be first Mcintosh piece and wondering what owners of this piece have experienced? Realize that numerous factors come into affect, cables, speakers, amplifiers, but thoughts and experiences would be appreciated, Thanks.