Hi guys, after all that’s been said there must be no doubt about the differences between using stereo or mono tracks!
What I’d like to add is that nowadays it is possible to record mono audio in a stereo track, and I believe Steinberg enabled this to avoid bigger problems for the users who do this incorrectly (adding stereo tracks to record mono signals).
In the past, this would result in a stereo audio file with the signal in the left channel only, but now it records a mono audio file normally as expected (by the user who does this way). I believe this change was made to avoid big problems, or for using factory VST AMP Rack plugin which should be added to a stereo track eventhough the input signal is usually mono.
Still, in my opinion, you should choose carefully whether you want to use a mono or stereo track depending on the post-processing you will make (insert plugins). By using mono tracks and mono signals, you have less DSP load and avoid routing problems inside plugins as mentioned before.
Cheers