I originally thought the advantage of PIC32 was the ability to handle more sophisticated RTOS, like ones that are linux based. Unfortunately it lacks a Memory Management Unit (MMU) and enough ram.
So now I'm trying to understand when would you pick a PIC32 over a dsPIC33?, aside from when you need a 32-bit processor
dsPIC seems more promising. It has a DSP engine, and the ability to have more than twice the amount PWM as pic32 (up to 14), and can come with a Quadrature Encoder.
Both architectures can come with a DMA, DAC, Digital communications (I2C, SPI, UART) and a Real-Time Clock and Calendar
Best Answer
dspPIC33 is intended for Digital Signal Processing applications - FIR/IIR filters, Fast Fourier Transform, Audio Effects Algorithms, ... PIC32 is intended for more "general" use - it can do everything that dspPIC can, but much slower because of the lack of MAC (Multiply-Accumulate Unit or in Micropchip jargon - HW Mutiply/Divide) and MMU can be always added to PCB. Microchip has some support for porting FreeRTOS to PIC32, but I haven't tried to yet.