To be perfectly honest I am not a particularly big fan of data managment system generally whoever makes them. As a design consulant I sometimes have to work on a client site which means that in most cases I have to develop an understanding of how that company utilises the system which can be quite stressful sometimes.
However, beyond tha I generally find it ok, it has come quite a long way and PTC is spending a lot of money developing the PDM and PLM products, some would argue at the expense of Wildfire. From what I have heard and this is not gospel the latest version is quite another jump. On the flipside though I also heard that the latest cut of Intralink has lost some of its nice features (i will have to wait and see, yipee).