Smartsheet

- Ease of Use - No need to involve programmers to create custom solutions
- Versatility - customizable sheets and dashboards for different departments and needs
- Support - AMAZING user forum, help pages, support department

Row and cell link limitations - I bump up against the cell link limitations often, although I can work around them by saving my metrics into multiple sheets.

Smartsheet is my preferred software for Gantt charts, and for quick & simple spreadsheets. The formatting features are especially effective, such as easy indenting and quick checkbox options that can be used with formulas. Gantt charts on Smartsheet are quick and intuitive with all the options I would like to have. Dashboards can be a nice way to have an overview with links to different sheets if you have a project with several documents, and are willing to spend the extra time and money to set it up.

The big Con with Smartsheet is that it lacks the in-depth features of similar spreadsheet software that is also usually freely available.
Conditional formatting the way you would like it to work can take a surprisingly long time, as it can take many conditions (often one per column per action) to accomplish what you would think would take a handful.
Automatic email sending from sheets sounds great but is still not very fleshed out, and options are pretty limited.
Complex formulas usually need to be done in several hidden columns or they can end up taking large paragraphs of hard-to-edit text and numbers due to lack of formula options. This can also make complicated spreadsheets pretty slow.
Bugs occur infrequently, but make me prefer to double check important sheets.