One the characteristics that set the Surface Pro 3 apart from other tablets is its versatility. It can do so many things well that, if you get the right one for your needs, it can be a laptop replacement and quickly become your primary computer.
A significant reason for this is the inclusion of video and USB ports, features that are missing from most other tablets. However, to be used as a real primary device, most Surface users would prefer an easy way to hook up to an external monitor and peripherals.
Microsoft has satiated this desire with their Surface Pro 3 docking station, but for those of you who may be looking for a more affordable (and portable) option, take a look at eTauro's USB dock for the Surface Pro 3.