@KeriI had time to look into this again today.  There is actually a way for you to download your clients' details to a CSV file with the following info.  You do so by going to the Clients dashboard and clicking on the icon (with an arrow pointing down to a tray) in the top-right corner (next to the gear icon):

• Name
• Type (of client)
• Work phone
• Home phone
• Mobile phone
• Email address
• Street adress
• City
• State
• Postal code

Note, however, these details were populated at the time you created the client.  Unless you subsequently go into the Clients dashboard and update these details for each client manually using the Edit client function found under ACTIONS, these details may be outdated.  Some may not be aware but there is no synchronization between the same details you update in your clients' tax returns every year and the data in the Clients dashboard.