It says anything you need to know about essential fonts, conflicting system fonts, etc. Now I have only three System Fonts installed and manage the rest (2.500 fonts) through Extensis Suitcase. Only a couple comments:
- If you replace the Helvetica font the new version may have a slightly different kerning or leading causing the iCal Icon Date to appear off center (a minor concern if you ask me).
- I think this has been mentioned before but just in case: Activating some "helvetica fractions" fonts may cause the headers in mail look awful.
- With Photoshop and Illustrator CS, you need to have an active Geneva (although not in the system folders) because it is used, not to show the labels, but the readings in the info palette. If you don't have this font open, the info palette of those apps will be shown as usual, but it will not give you any values at all.
- Geneva also has some obscure relation to how Suitcase X1 preview pane resizes to display multi-linear and large sized examples. Apparently Suitcase uses Geneva's leading instead of the particular font you are previewing to set the height of the preview space assigned to each font, deactivating Geneva makes previews look "croped". With this font open (even in your Classic folder) Suitcase's preview will work just fine

