We are a small company that coordinate several projects in parallel. Without a whiteboard in a conference room to manage our work, we were looking for project management at an affordable price. Sprint Ground was the clear winner!!!
Pros: Optimized for Agile, free for up to 3 users, all tasks can be filtered by a host of variables like status and due date
Cons: limited projects and disk space due the plan
We've used SprintGround for multiple personal and business projects now, and so far we are very satisfied!