If you are in an enterprise environment where you depend on SharePoint as a development platform then this offers many capabilities that other solutions do not. If all you do is use SharePoint as a web-enabled file server then this probably isn't the right tool for you. In our environment it is critical that we can perform item level recovery while maintaining those pesky GUIDs that Microsoft developers are so in love with. It is also imperative that we are able to perform an out of place restore to other environments at even an item-level. This is where the product really came out over the competition. Most other products were very limited with out of place restores being limited to a database-level only. DocAve is more than just a backup tool there is an entire suite of products such as Content Manager, Report Manager, Deployment Manager, etc. These tools can be very helpful to both your SharePoint Administrators as well as your developers if they tackling SharePoint for the first time.
The user interface is not intuitive. It is clunky at best. It is a significantly more complex tool than your typical point-and-click. As with most other products you don't really have a good single backup for all your needs. I find myself taking two backups to meet our needs. AvePoint calls these (Platform-level and Granular-level). Platform is really for disaster recovery needs (restoring at the highest levels) and Granular is for the day-to-day recovery of items that might not be in your recycle bin. The names are misleading in that both Platform and Granular offer item-level recovery if configured correctly. While you can perform a granular item-level recovery from a platform backup it is not optimal. Support was better in the earlier days of AvePoint than as of late. As AvePoint has grown they have become less responsive to fixing things for the sake of making them right. I guess they are picking on the bad habits of Microsoft. The tools does rely on a tradition streaming over the network backup. If you want to make use of hardware based snapshots (like NetApp) via your SAN you will inevitably find yourself looking at a rebranded version of DocAve such as Tivoli for SharePoint or NetApp SnapManager for SharePoint.