Trees, rocks and other idiots slamming into your melon will kill you , I have music and phone integration which is convenient and it keeps me warm and safe.
After a few hours you won't even notice it
For me, even on days like yesterday when it's 55* spring slush, no tree riding, etc... I still wear one, because there's always that chance of a collision with another rider.
If you're going to wear one, wear it. It only takes once. That's my take.
I too have Bluetooth phone and music integration in my helmet.
Actually for the first time last weekend the helmet actually saved my head. I top head planted on a cat track enough to yard sale everything. IF that would have been my head I might not have gotten right back up.