Michael_Heyns can you please feed back that the toggle to the "old" (a.k.a. actually usable) comments system should not be a temporary thing?
The problem with modern comments is that, in addition to the utter destruction of established workflows, they bring literally nothing whatsoever positive in return.
I, like many people here, work in Word with comments not for fun, but for a living, and this change has a direct - and negative - impact on how I do my daily work.
There are many things in Word that need far more urgent attention (e.g. a caption system that actually keeps captions attached to the things they're captions for; the 1995-era style manager; the miserable performance with large documents containing many tracked changes; the utterly byzantine reference editor; the slow descent into madness that is numbered list styles). I think I'm on safe ground if I say that if Microsoft had never changed the Word 2016 comment system ever again, pretty much no-one would have cared.
All I can do is implore Microsoft to reconsider this change, or at least make it permanently optional.