I have used SharePoint for a few years and, for the most part, it works well. However it is extremely flexible and can be customized to do pretty much whatever (assuming the SharePoint consultant you hire knows what they are doing).
I have no idea how integrated SharePoint is in the systems where I work but 2500 employees on three continents are able to share files fairly well (there are size restrictions that keep us from using large files, like 3D scan data, with SharePoint).
All CAD data is controlled via Windchill so the SharePoint functions are limited pretty much to MS Office documents. Like Windchill (or other PDM) you can check in, check out, and control revisions.