All

I mainly found it to be a problem riding really steep stuff or in deep berms. Couldn't get my head round far enough to see the next section of trail. As soon as I became aware of it I found it hard to not be distracted by it.

I finally got a used one just in time for my last mountain bike ride at Vital Ditch Day a few years ago. I wore it without all of the fancy straps and had no issues with comfort or it hitting the back of my helmet.

There was a 10 year study on neck braces that everyone should read - https://www.actionsportsems.com/case-study-neck-brace. I've been wearing one for years. As far as freedom of movement etc - invest the time in setup and also have your brace on when you're trying out helmets to check for interference.

I currently do not wear one but I should. A Leatt brace saved my life after a Kona dh bike (Operator) snapped, I almost broke my neck. I was lucky enough to receive only 2 fractured vertebrae. The doctor said without the leatt brace, I would have snapped my neck and potentially been paralyzed. Now I’m the jack ass like everyone else wanting comfort. I have forgone wearing a leatt I will prob start wearing it again.