If you're not averse to CLI and some tinkering, i think khal may suit your needs.
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I switched to using Radicale a year ago, and I use my android contacts app to add and maintain that info. CardDAV has enough fields for me to add.
The only address book I know is thunderbird any maybe the GNOME or KDE suite (their Personal Information Management (PIM) Suite).
Maybe the small desktops have alternatives.
Thunderbird supports CardDAV for syncronizing contacts too. But it is unencrypted so I wouldnt use it.
Etesync is encrypted.