I have the Troxel Sierra - I like the look of it and the ventilation is good. I wish it fit a bit better but I think the adjustable band does a good job.
I hit really hard at the beginning of summer - had a concussion and brain-bleed and won a 4-day stay in the hospital for observation. This was in a sand arena, and you can see where the helmet absorbed the shock. No splits, but there’s a flat spot and a dent on opposite sides of the helmet (landing and then the shock moving the material). I landed on my back hard enough to bounce and flip over onto my front, and lost about 15 minutes of memory. Happily I healed pretty well and uneventfully and bought another Troxel Sierra - I figured hitting that hard and having relatively minor injuries was a good recommendation.
However - it all depends on the shape of your head and having the helmet properly adjusted to fit. So get a helmet that fits your own head and then wear.it.every.time.
Rosalie