Settings in a portable install are stored in ini files under the program's install directory:
User Settings.ini
Machine Settings.ini
This is wonderful, assuming all the stuff that is otherwise stashed here and there is in one place for easy and reliable backup, transfer to another PC, etc. (Meaning, the user data that is "normally" put in various user-specific Windows folder and the Registry, difficult to track down and even more difficult to manage.)
Is there any reason to NOT use Portable installation mode in a non-portable situation?
Ideally, MC would either default to always using .ini files in a fixed, documented location, or allow the user to select this mode even if not "portable", and/or allow the user to specify the path where .ini files and other user-controlled design/config is stored.
(My comments are driven by the ongoing extra steps to keep multiple PCs synched to use the same smartlists, view designs, display/track info designs, photo captions, library design/fields, library backups, etc. via a mix of overriding MC default locations where possible, and complex backup scripts to pick up most of the rest, with the Registry stuff the most painful...)