As of recently I bought an Arduino Due and have been testing it out on a few projects. It contains a SAM3X8E micro-controller with 54 digital I/O pins 12 of which are PWM. The device itself is very interesting and I haven't had any problems running it so far. With such a powerful micro-controller it's enabled me to be able to learn how the Due works especially as an embedded system. With it I've been looking a lot into lower level programming and how the Arduino libraries are utilized. I've also been able to test out things such as using different clocks, communication through USART and referring to the Atmel data sheet and Arduino pin mappings and schematics for different designs.
Overall the Due is a really nicely designed board which has allowed me to further increase my knowledge in electrical and embedded applications. Hopefully it will be able to reinforce my learning about lower level programming and further testing will allow me to create some interesting projects.
Arduino Due Main Page: http://arduino.cc/en/Main/arduinoBoardDue