Intelli Enterprise has been evaluated against many competitors but it ultimately offered the best mix of budget, functionality and versatility. It is easily one of the most feature rich products offering features for people, documents, storing/managing your data and workflows. You could use this as an enterprise social network, company portal and extranet all at once.
We have a very special Active Directory setup that needed to have fields and groups remapped to other fields. Their support helped us do that by instructing what configurations we need to change. There are a quite many things you can configure and change which despite their manual can be confusing at times -- but at least it's completely code free out of the box which we couldn't say for any other vendor that offers this much flexibility. Bottom line: 4/5 stars
Features, features, features. They have so many and everything can be somehow customized or tweaked; if not in the UI than through their helpful tech support
The forum and IM function. Both these look and are very basic. They need to update those.