smartsheets advanatges and disadvantages?

Smartsheet is a software as a service (SaaS) application for collaboration and work management that is developed and marketed by Smartsheet.com, Inc. It is used to assign tasks, track project progress, manage calendars, share documents and manage other work. It has a spreadsheet-like user interface. As of November 2014, Smartsheet is used by 5 million people at 55,000 organizations. It was initially unpopular until a re-design in 2010, which was followed by an increase in adoption and larger funding rounds.