In reply to neuromancer: Salamander does come a bit lower down at the back than most designs as it's not a straightforward puddin' bowl shape, which I quite like. No substitute for trying on as many different ones as you can though...
Also, worth reading the recent gear review on hardshell and foam helmets, iirc the foam ones can perform better if the main worry is you falling, as they're generally better for a side impact, whereas hardshells are more geared for an impact on the top (ie. falling rock, gear, partner etc). Don't take that as gospel though, seek out the actual article.