It has a quite differentiating feature called real-time-update, which is now shared by google and numbler only. Moreover, you’re allowed to address your spreadsheet with a human readable url like: http://www.editgrid.com/tnc/pkchan/EditGrid_v._Google, and if you append “.xls” to the end of the url, you’ll get the exported version immediately. Quite distinctive.

So you may wish to mention this one also!

=)