What I look for in a witness first and foremost is communication of what they are doing. If they are unable to do that because of time constraints, having some sort of public relations is essential to me. A good example of this is @jerrybanfield's post today showing what the top 10 witnesses are up to. I also make an effort to promote and support witnesses who I know are working hard for this community. (How can I vote for you if I don't know what you do?)

Number 1 also is integrity. When I see the efforts witnesses go through to help others, it gives me confidence that they are not just here for the payout. So I suppose I judge integrity by what type of service these witnesses bring to the community. It is easy for me to see how helpful people like you @drakos, @rycharde, @reggaemuffin, and @netuoso are. (incomplete list, just who came up off the top of my head)

I will include the ability to act quickly when the community experiences crisis. many witnesses got my vote during the bandwidth crisis, simply because I knew that they were there for the people who lost service during that time (above mentioned included in that list but many more I mentioned in my "easy witness voting guide" at that time)

Willingness to take a moment of time to answer the concerns of the community, bandwidth crisis, for example. More current would be the "Voting Abuse" crisis, which you highlighted from the new whitepaper is part of the role of witness.

I will come back here and update this comment if I can think of any other "essentials". Thank you for everything you do @timcliff!