Digital Vs. Analog Phase measurement
Digital has one major challenge for control application: latency.

Any digital system needs to include A/D conversion, processing and D/A conversion. The minimum amount of latency is 1/SampleRate even if you don't do anything else but a straight wire. You also typically can't use off-the-shelf sigma-delta-converters since these have significant amount of conversion latency.

Most digital control systems tend to use heavy oversampling and fast one-shot converters to work around this problem. Once you have the basic infrastructure in place, the digital domain offers a large variety of algorithms that are highly configurable and effect. However the cost of entry is high.