Used the guac to host 100+ sessions for researchers and devs at my previous company. Performed well and using docker made it a breeze to deploy in the cloud and it also tied into my IPA infrastructure nicely for central authentication. I did not play with the screen recording feature though.
I would treat this as a bonus question, but not a required one to answer. If the interviewee is on the right track with a lot of good DNS questions and you throw this one at them, it might set them out from the pack.