The 3D printed samples look very nice the way they are shaped, they're color adds to the way they look. They seem very durable and without major manipulation hold together strongly. They serve the purpose they are built for. When it comes to they're complexity, the way they are put together is very intricate. Knowing how a 3D printer works, you can obviously see the individual layers is very cool.  You can see basically how they were built up and and in which direction the machine operates.

From prior knowledge of 3D Printers the time necessary for a design or concept to be printed, even as small a quarter, is extremely long and almost monotonous. So when it comes to larger and more intricate designs the time could take up a ton of time. With more and more limitations being overcame such as printers going from plastic to metal, metal to concrete, and even to organic material such as cartilage from humans (see image below). The application has fewer and fewer limitations every day. Obviously time limits how quickly something can be built, but also the fact with certain objects, especially those that move, need to be built piece by piece. So definitely the application to the real world for 3D printers is almost endless, but restrictions can definitely take away from the usefulness of the printer.

Scientists at Princeton University are being very innovative and creative with the 3D Printers by using them to basically create "bionic ears". They are adding together “bio-printed organic materials” and electronics. These bionic ears are said to perform better than average human ears and can be used as replacements in the cases where people lose or have to remove this type of cartilage that is a key body part for our sensory systems.
http://www.huffingtonpost.com/2013/05/07/bionic-ear_n_3224379.html