It's easy to use and it has all of the features I need for my day-to-day activities.
The support is very responsive, so any problems are dealt with quickly. There aren't many downsides - other than that I wish there were more templates available! One thing we've found useful during our transition from manual tasks (manual invoicing) to automated processes was having an accurate estimate of how much work would be required before implementation (so we could budget accordingly). This allowed us to plan ahead and prepare for changes in workloads without resorting to overtime or hiring additional staff members.