I like the idea you’re presenting here, in terms of what it would enable.
I can also say, as someone that semi-regularly posts reviews of gear, some of them pretty extensive, that there is no way I’d fill all that out in the form necessary for it to work as structured data. And even if I did, absent a big guide, or additional context (both of which entail additional work on the part of the reviewer) you’ll still get subjective and/or incomplete responses.
For example, unless you have a range of values specified then things like “Cable: Weight” will be useless as what one person considers heavy won’t gel with another person’s opinion. And if you think I’m going to pull out a scale and measure that for every headphone I want to post a review or impressions of … well, let’s just say it’d result in me never actually getting around to making the post at all.
My impressions or reviews might include such things anyway, and I agree it’d be great to have them processable, but having seen how this sort of things tends to go when those having to do the work are faced with that much structure … my expectation would be that you’d get great data on very few reviews. Per @pennstac’s comment, it’s hard to get people to observe that much rigor even when you’re paying them.
And then the degree of time/effort I, personally, am willing to put into a post on impressions or a review is highly dependent on what item we’re talking about. I’m going to say and provide a lot more information about a $4,000 set of headphones than I am a $100 set.
Having a “Headphone Database” with such specific information in, that then links to the more common narrative reviews might service both goals. I think having a list of information that is good to include, with examples, such as that you provided, would also be useful. But I do believe making that a necessary part of posting impressions or a review will simply result in people not bothering and just posting their thoughts in the product threads anyway.
I’d add that, perhaps for gear made available via the Community Preview Program, you might be able to get people to fill out some of that … but I’m hesitant in thinking you’d get everyone to do it all.