I think the best about the AVR controllers and other ATMEL products is that the datasheets are top-notch because they contain all necessary information to use t

I think the best about the AVR controllers and other ATMEL products is that the datasheets are top-notch because they contain all necessary information to use the device/peripherals in a concise and readable style. It is usually difficult to read the entire manual of an ARM Cortex because of the sheer volume and because the documentation tends to be split over several documents. For an AVR chip, you can easily flip through the entire datasheet. As to how excellent and powerful the AVR peripherals are -- there are some strange peculiarities and limitations which ATMEL never addressed, for example the strange SPI/slave behaviour: http://rpc.gehennom.org/2013/09/atmega2560-as-an-spi-slave/ http://rpc.gehennom.org/2013/09/atmega2560-as-an-spi-slave/