I'm seeing a lot of people listing The Vortex as their least favorite ride because of head knocking. Given the topic you all are completely entitled to your opinion, but I wonder how you've been sitting. I understand that rides with OTSRs usually have instructions posted in the que or stated by staff to keep your head back against the rest. My experience has been that this very thing makes for a painful ride. When I lean forward with my chest against the restraint and head slightly forward, I notice that my torso tends to keep me in place and when my head does move, it does so without knocking into anything. This has been my experience with other Arrow coasters as well as B&M (Raptor, Mantis, Dominator, etc.) and Intamin (Maverick) rides with OTSRs. If you haven't tried this, give it go.