I have tried the beta of Google Spreadsheets and am generally impressed. But if you’re a spreadsheet author rather than just a consumer of spreadsheet data, don’t throw away your copy of Excel quite yet– there are still compelling advantages that only a rich client can provide.

What we really want is a hybrid of rich client and web based spreadsheet models that provides both reach and richess. Regardless of how they were created, documents should be accessible collaboratively by anyone with a web browser, and for many users the browser will be all they need. But document authors who care about a rich, highly responsive authoring experience should have the option of installing a native client to provide those features, with technology such as .Net, Java, or Flash possibly serving to reduce the installation issues traditionally associated with rich clients.

On the pro side, Google Spreadsheets definitely the nicest of the online spreadsheets I have tried. Cell selection and editing and keyboard shortcuts work for the most part exactly as you’d expect, though there are few omissions (e.g. HOME and END do not work.) You get the expected benefits of web based applications– no install, the ability to access your data from any computer, and the ability to share and collaborate with other users on the web. Two users can even edit the same sheet at the same time. Multi-level undo is supported, even across different browser sessions. You can import Excel documents from your desktop, including ones with multiple sheets.

On the con side, features that experienced spreadsheet users rely on aren’t present and some of these features will be difficult to add within the constraints of a web based application. Scrolling is a bit sluggish and has a “ripple” effect for large spreadsheets. There is no autofill, autosum, filtering, or drag-and-drop moving of blocks of data. There is no conditional formatting, charting functionality, or pivot tables.

Who gets to the ideal hybrid of web and rich client access is a difficult call. Can Microsoft produce or partner with a web spreadsheet service and adapt Excel to save documents with high fidelity on the web? Will Google or Sun adapt OpenOffice or other technology to work with its spreadsheet? Or will the universal browser platform become rich enough to do highly responsive spreadsheet authoring, via the addition of a spreadsheet form element?