My neck pain is helmets that restrict my forward vision because they come too low on my brow or have a visor.
I made a mistake with my last helmet purchase and it comes a little too low on my brow. So when I spend a lot of time in the drops, I get that strain from having to crane my neck in order to see far enough ahead.
I'm about to go helmet shopping again and will make sure I get in my riding position in the drops to see how much I have to lift my head to see in front of me with each helmet.
A previous helmet I had years ago had a removable visor on it. Removing the visor solved all my neck pain. Too bad I smashed that helmet and put 11 major cracks in it. Also put 3 minor cracks in my skull. <grin>