LMI:
A PWM output is probably lower quality than a DAC.
This is what Teensy says about using the PWM as audio output:
The PWM carrier frequency is 88.2 kHz. The suggested circuit will only slightly filter the carrier. Extra filtering will be required for a clean signal without the ultrasonic PWM carrier.
Analog signals created by filtering PWM waveforms use the digital power supply as their reference voltage. Any noise on the digital power line can directly couple to the output signal. The built-in DAC or audio shield should be used when higher quality signals are needed.