Even though I have nothing to do with maptesting, this is seriously awesome in so many ways, for you guys, dying for feedback. Brilliant great job, I'd say.
You have no idea. Ingame i might only hear 3-5 worth while comments probably also drowned out by static, and because i also wont know where a player is when they are made it's difficult to deduce what they are talking about without faffing around with the demo for nearly an hour.
After testing this plugin in the server i noticed i had 25 annotations in my map that were pretty much all helpful, compare that to the zero comments in my map thread since my last release a month ago or 2 or 3 obvious comments a map might get in game like "oh, missing texture" or "no cubes". It's amazing.