Analog vs Digital Accelerometers - pro's and con's?
The biggest difference is where the measurement (the conversion to digital) is done.  On the digital accelerometer, it is done in the accelerometer itself. On the analog one it is done at the MCU.

For simple arrangements where the accelerometer is near the MCU that makes no difference. However the analog one is more susceptible to noise. With longer wires / traces between the accelerometer and the MCU you can get less accurate results with an analog one since it picks up noise which you are then sampling and including in your results.

The digital one is more immune to that kind of interference - instead it is susceptible to digital noise - corruption of the data as it traverses long wires. But that is less of a problem since it takes far more induced voltage to corrupt a digital signal than an analog one.

One other main difference is that you are limited to the ADC that is in the digital accelerometer. If you want a different resolution you have to use a different accelerometer. With analog, since it has no inherent resolution, you sample at the resolution of your MCU's ADC.

Digital is also easier to interface in modern systems.  Many SoCs don't have analog inputs. So adding an analog accelerometer would mean adding an ADC chip as well - and you don't really want to do that in something like a mobile phone.  

So in summary:


Digital is the most convenient, reliable and suitable for current basic uses
Analog is more of a niche product that is rarely used in consumer electronics