Throwing in the webcams, eye-tracking, or what-haves-you IMO incorrect lends an air of specificity and scientific-ness that isn't warranted.
Before we launched our last product update we brought people in to use the app. It was very much as you described - we invited them to come into the office where our PM sat with them, watch them used the app, and asked good questions.
The much more subtle behaviors are IMO not determinable via pseudoscientific things like watching facial expressions, eye movement, heart-rate, or whatever these things are supposed to measure. Best A/B test for the rest.
Including this, very well put, pseudoscientific things, on the qualitative phase must do more harm than good. Maybe they act as an excuse not to really test the assumptions.
One trend I have noticed a lot in Berlin is money being spend in all sorts of things that are in no way related to the product or service the startup was trying to create - and the few times I dared asked I got the same "they are investing a lot of money on us man, that party should better show it!".
While the investors think: "If they don't spend all our money I will think they are lowing the chances that this investment will pay back, so they better spend it all".
But then I remembered, I did this myself! At home. With my father. In a much leaner way.
I am a sole founder, working at home, while my wife pay for our bills (all that to say, I have no money to invest). My product is sort of "online pills dispenser as a service", a SaaS B2C helping elderly people organize their medicine. And my father is just my target (actually, I started all this thinking of solving his problem). When created the first version I went to his home and let him use the site. I just typed the URL and then just kept watching. He pains attention to details, so I left, one hour and a half later, with literally more than 50 notes of changes that I should made. From small design and copywrite details, to whole new features.
And you don't need webcam, microphones and a soundproof glass. This is the case if you have bosses for whom you must report. If you are the founder, just you, there, taking notes(and asking the right questions) while the user experiment your product, it is enough.
If your friends are the target, your house is fine. If you must talk to strangers, a public computer is enough. Even Eric Ries on his book talks about customers going to their office to do this - not a whole "usability room". Sometimes I think funded startups spend their investor's money just for the sake of it.