No Fog for sure. Was up on the Ride-In weekend and it was cold. Went to see Chad on Friday morning at M&M thinking about getting a new helmet as I had a lot of trouble with my lens frosting up on Thursday. I was going to ride with some guys Friday and didn't want to be the guy slowing everyone down because I couldn't see anything. While he would have been happy to sell me a new helmet he suggested I try the No-Fog first. He said it would work with my closed helmet, but if I came back and still wanted the open face it would work great with that too. So instead of spending $200+ I started out with $35 and it was great. Later that day I went back to buy another one to bring home to my son and Chad had sold out that day. Ended up telling some other guys about it and we ordered 5 of them from Dennis Kirk. We were all up on Presidents Day weekend and everyone said they were great. Some guys had open helmets, others had closed and no one had a complaint. Yes you do take the deflector out of the helmet, and it's not as quick to put on and off as a balaclava, and sometimes I ended up leaving my helmet on when we stopped as it's a little more of a pain to pull a closed face helmet down over it, but I have to say for the money it's one of the best things I've bought in the past few years. I still wore a thin balaclava under it as I like the feel of a balaclava all around my head but I'm sure you could go with just the No Fog and be happy if you'd like.