My Take
As a teaching tool, PearDeck is great. I like that I can upload slideshows from Powerpoint and Google Slides that I have already created and add questions to them quickly. The free version isn't limiting at all, which I appreciate, and the students have fun answering the questions. It is easy to use and to teach students and teachers to use as well -- Oh! And it doesn't require students to actually "log in" which is a great time saver!
How I Use It
In classes, we use PearDeck for our classroom read-a-longs and lectures to gauge student understanding and to keep our students accountable and engaged. We have use PearDeck during professional development as well instead of a traditional slideshow to get poll results.