You have a great integrated platform however I find that it is missing some VERY KEY ingredients in order to be broadly adopted to google apps users and other platforms.

1. IMAP Email for accounts other than ZOHO.com accounts, so email migration from other systems can occur. This is a must.
2. Shared Calendars
3. Bulk upload of files and folders.
4. Iphone - Exchange sync of contacts, calendars.

Thanks!