In no particular order, here are some desirable features:
1) Version control.
2) Access restrictions and permissions. BONUS: Responsibilities, a la Siebel and other CRMs.
3) Simple drag and drop manipulation of data, such as concatenation.
4) Wufoo-like ease with building data entry forms.
5) Dummy data mode, so you can get help with customizing a complicated spreadsheet without revealing sensitive data.
6) Example use cases for sophisticated features, with well-written instructions, INOW a good, non-linear tutorial.
1) Version control. 2) Access restrictions and permissions. BONUS: Responsibilities, a la Siebel and other CRMs. 3) Simple drag and drop manipulation of data, such as concatenation. 4) Wufoo-like ease with building data entry forms. 5) Dummy data mode, so you can get help with customizing a complicated spreadsheet without revealing sensitive data. 6) Example use cases for sophisticated features, with well-written instructions, INOW a good, non-linear tutorial.