The beta status of Zoho's applications might also be an issue for some. I'd hardly call Google Docs bulletproof, but Zoho did seem to freeze up the browser more often (though a page reload would usually solve the problem).
Zoho's real strength lies not in the merits of its individual applications, however, but in its offering as a whole. In addition to its productivity suite, Zoho offers a whole range of back-office business applications, including groupware, conferencing, invoice management, project management, CRMCRM, and more. Most are free for limited use with a modest amount of storage space; for increased capacity and a greater number of users, Zoho charges a per-head subscription fee. Alles zu CRM auf CIO.de
As such, Zoho could appeal to small businesses who like the idea of a suite of a la carte business applications that don't require a dedicated IT staff to install and maintain. Although it seems unlikely that Zoho's online productivity apps will meet your needs as well as desktop software would, if the SaaS way of doing things is attractive to you, Zoho could be a cost-effective option that provides a wide range of business functionality with a minimum of hassle.
Zoho's support for Microsoft Office file formats (above) and Excel 2007 embedded graphs (below) is better than that of Google Docs, but only slightly. (Note: Click the images to enlarge them.)