Ease of use, easy integration, great customer support, easy to learn and solid documentation, and many more.
Reports are easy to generate and there are so many resources to help answer your questions. The provided training videos are clear & give good direction.
It is very intuitive and has a great mobile app. The price is also great considering all the features.
I hate the way the tagging system works. I hate the data import/export process is over complicated.
The lack of a quoting interface, manual address entry into Quickbooks, lack of phone integration, and incomplete email integration.
No offline desktop apps. There was a feature I was missing on the iPhone app but can't remember what it is.