Feedback is complex because it comes in different forms and irregularly. Different feedback have different themes (product, process, etc) and timing (now, later, etc). Feedback is also biased based on the giver's world view, and sometimes what he or she says is indicative, not prescriptive.
Feedback is complex because it's hard to process the above and weight the feedback accurately. Do you weight the feedback that is timely more highly than feedback that isn't? Do you weight feedback from experts more highly than those from non-experts?
I think of processing feedback first as a classification problem. I classify feedback based on certain themes (product, process, team, strategy, or fundraising). They may even be in an 'other' category that is outside of my world view, but could be important. Classifying feedback first allows me to try to figure out what the giver is really saying, not what they just said. I also try to disregard who said the feedback and classify feedback based on the insight, not the giver.
I then weight that feedback based on the giver. Every giver has bias, whether he or she knows it or not. The good feedback givers state up-front what biases they may have, the normal ones don't, and the worst ones intentionally push their feedback despite their biases. The two biases that may show up is geographic and stage bias. Usually certain feedback can pertain well to certain geographies and stages in startups.
One way to weight feedback is to say - based on all the feedback received, what is the 1-2 that you resonate with? I realize that this is an imperfect way to weight, but the bottoms-up method of weighting (assigning percentages) is oftentimes inefficient and subject to the same biases that a top-down method will have anyways. When bias is the same, go for the method that is more time-efficient.
The one thing I tend to disregard is timing. Good feedback is generally time agnostic, unless it deals with fundraising or introductions. Fundraising is relevant because certain industries may have already been funded to the hilt, or a certain intro is no longer relevant because that person has moved on.