As a first AMS for our organization many years ago, WebSuite did everything we needed it to! Customer Service is great and our needs were always addressed in a timely manner. Now that our staff and functions have grown, we require more complex functions for an AMS to meet our needs.
Constituent data was easily accessed and modified and queries were easily built with the ability to save reports accessed often. Built-in emails and invoicing was nice to have, though templates were very basic and could not be modified by our staff. The website we orginally designed was not able to be updated unless we paid a "rejuvination fee" and we felt that should be customizable at any time. Any basic text changes could be made to the website by our staff but additional pages or layouts had to be done by the company.
If you need a good place to start, WebSuite is a good option!