[dcb]

Doesn't teensy use the horrible Arduino IDE?.

It truly is though. MBed is a lot better if you want to minimize toolchain installation headaches, and have a semi-normal looking paned IDE. NXP already has a k66 mbed offering

https://developer.mbed.org/platforms/?

Oh and a k66 cpu itself is like $16, and an atmega328 is $1.60.