Though I hadn't had the opportunity to use the new Google Slides Q&A feature with my actual students when it came out in May, I did decide to try it out at the KBEA Conference this summer when I did my Google session. If you haven't heard about it, you can access the new feature by pressing the down arrow next to the Present button. And, you have to tell it to use Presenter View. A URL appears at the top of your presentation that participants can visit on their phones (or laptops) to submit questions. They can see each other's questions and even up-vote them if they also have that question.
When you use it, the default is that only people in your organization can submit questions, which is fine if you are a GAFE school and using it in class with students who are logged in. However, in a presentation situation, I had to change that to be "anyone" instead (it was a simple drop down).
Also, the presenter view pops up on your screen, so I suppose you must do some sort of "extend desktop" on your presentation computer/device to make it where only you can see the questions. After using it, I might would just minimize it and then have my phone open to the URL where they submit questions so I can see those separately.
Finally, you cannot exit the presentation or the questions disappear (and the next time, a different feedback URL appears). I learned that the hard way. Although, I also learned that you can also go to "Tools>Q&A History" to access the questions.
It's a pretty neat feature! Even if your presentation isn't in Google Slides, you could make a one slide presentation just to start class (a welcome screen, if you will) and allow students to use this to ask questions about whatever topic you are discussing (or about a PowerPoint that you are using and not a Google slideshow) provided you don't exit the presentation. I think there are some great implications for using this somewhat as a back channel (except you can have students logged in, which is cool).
Thoughts!?