I don't think Mormons ever talk about these garments either. Every comment I've read about Mormon underwear has been written by non-Mormons and there seems to be a consensus among non-Mormons that Mormon underwear and garments is weird and awkward. I don't agree but I also understand that this is a natural response, we all are surprised when we learn about something that is different from us and what we are used to.
What non-Mormons are most concerned about though is that some Mormons believe that Mormon underwear has the ability to protect from all evil. For example, I heard that if a Mormon has a car accident and comes out of it safely or with a minor injury, it is not unlikely for him to believe that it is because of his garment.
It's good to know what non-Mormons think about Mormon underwear, but I really wish we could hear about it first-hand from Mormons themselves because no one else will be able to explain this practice better than them.