Torch is right, go with a Sweet Rocker. I took a good head shot last week and it did a great job of dissipating the impact. That blow with a Strutter would have rung my bell good.
If you search the forums for "helmet" you'll find several long discussions on the matter (plastic vs composite, impact protection, etc...)
If you have the $ go for the Rocker, if not the WRSI or SR are great economical options.