Arduino Uno with a 32-bit ARM Cortex-M0, LPC111X NXP microcontroller in 28 pin DIL package instead of Atmega328p
The nice thing about Arduino Uno is that not only it introduces you quickly in the world of 8 bit AVRs (Atmega328p) but after running a few programs, mostly already available examples, you quickly realize you can develop you own boards using stand alone Atmega328ps chips and you no longer need the Arduino Uno, excepting as an ordinary ISP programmer.
Arduino Due is not the same affair. Migrating from it to a stand alone SMD ARM with many pins, like the one installed on Due, is not an easy endeavor. You need serious skills in crafting PCBs to have your own ARM powered controller board, all this because of the hobbyist unfriendly chip package.
However, there is, at least in theory, a 32-bit ARM Cortex-M0, LPC111X NXP microcontroller in 28 pin DIL capsule that is as easy to use as an Atmega328p. See: http://www.nxp.com/documents/data_sheet/LPC111X.pdf
If it is worth replacing the Atmega328p on Uno with an LPC111X it remains to be seen. There will be a gain in speed, for sure, at least for code requiring many multiplications of 16 bit values integers that can come from the DAC.
What other advantages, disadvantages such a Uno with LPC111X could have?