No, not every helmet is equal. All helmets are required to meet the minimum standards, but that doesn't mean they are all the same. Helmets with "in-molded" shells, more plastic on the outside, and thicker foam are more protective, in my opinion, than those with taped shells and/or minimal plastic shell/minimal foam. But they do meet all the minimum standards.
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Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --
the tiniest sprinter