If you are in the process of developing a game, how useful would raw, annotated footage of a person playing your game for the first time be?

If a player provided this without you asking for it, on the assumption that it might be helpful, how would you take it? Would this be useful? Would you find this presumptuous and self-important?

Some context: This week I played the alpha version of an in-development game I follow on Greenlight. The version I played is a test bed for player feedback that will affect the final game.

As an experiment I decided to record myself playing it for the first time. I then wrote some pages of notes describing how I felt and what I thought of the game at specific, significant timestamps throughout. This meant that all my notes were as close to my first sincere reaction as possible. The complete video was just over 20 minutes, with 8 pages of notes (that could probably be trimmed down).

My behaviour in the game included me both sincerely playing the game as normal, as well as some attempts to abuse the game's features to see what happens. So if I encountered a bug, I would describe how I got that bug to happen. If I disliked an aspect of gameplay, I described my thought processes on why I disliked it. I tried to be as detailed and clear as possible, while also avoiding criticism that I suspected was unnecessarily harsh in its tone. So more, "I did [X] which caused [Y] to happen, which undermined the feel of [Z] feature", and less "[Z] sucks because [Y]".

I would like to share this with them, on the belief that it might be useful. However I'm very cautious that sharing this unprompted might come across presumptuous, almost arrogant, for being unrequested. I'm just assuming the team involved would find value in it. Plus the extensiveness of the comments might seem blunt and harsh. The version I played did in fact have a lot of issues, right down to the core gameplay experience, which I feel really need to be addressed.