Customization: A SA can be structured to automatically exclude investments an investor may own in another account or investments an investor would prefer not to own. Includes ability to negotiate the fee with the money manager?
Tax efficiency: A taxable investor can have their specific tax concerns addressed.
Transparency: the investor knows exactly what they own.
Manager access: an investor should have direct personalized access to the money manager(s) overseeing the SA. This could be through in-person meetings, conference calls, written commentary, etc. Professional money management valued in era of diminished, less easy gains from the market