This one was beat to death on the old site. I think is was from the May issue.
The big problem is that both sides have strong points as well as having holes in them. There are still many fingers being pointed and there have been many articles written for both sides that seem to make sense. Many Snell helmets may be too hard and not cushion your brain enough. Many DOT helmets may not survive the initial impact and provide any protection for subsequent damage during a wreck.
Much of the work done for Motorcyclist Magazine was done by a person who was an ex-Snell employee and there is obviously some very bitter feelings between the two. This is unfortunate since you don't know how much this sways the science.
The bottom line to me is that I have seen many wrecks with cheap helmets and many with Snell approved helmets and more have walked away from the Snell helmets than the others. I have seen cheap helmets crack from a drop from the handlebars. I understand the "soft" argument, but, after watching enough crash videos, I also understand that you don't simply hit the ground and it is over....many impacts can occur as well as a constant grinding.
Fit is still the king, regardless of standards. A helmet that doesn't fit your head will not protect you, regardless of certification (or lack there of). Many cheap helmet use a single outside mold while many more expensive helmets change as the sizing does.
I would love to see something in the middle....oh....we have that.....it is the European standards. My next helmet will most likely meet those.