I come at this from the perspective of trying to make sites (intranets and portals) that really help people do their jobs better. I have been working with small/medium-sized companies who have invested in SharePoint and want to leverage it. In general, I have found that with the possible exception of Collaboration sites, SharePoint out-of-the-box has what I would regard as such sub-optimal usability that in order to design an intranet that will really be adopted, there is no option but to do significant modification around even the out of the box element (document upload and document libraries for instance). The intranets we have developed, while they have been extremely successful, look nothing like SP and took a lot of design and development effort. As I'm not a techie, I'm not really aware of the technical benefits of SP vs other systems but I think it's really quite hard to get the SP front end to something that's usable in a really compelling fashion.