These objects test your printer's ability to bridge long distances. The two provided objects test bridging over 150mm and 200mm gaps.
If you can bridge the 200mm gap, you're doing well.
The above photos are ABS, printed with a .4mm hexagon hot end, .2mm layers and my print cooling fan shroud:
http://www.thingiverse.com/thing:351280
YouTube video of the 200mm bridge printing:
The author marked this model as their own original creation. Imported from Thingiverse.