In principal I totally agree with all the answers above, but
if you can get your resists up without good resists in your headpiece
if you have HLD on your weapon(s) of choice
if you max out in STR and DEX in other ways and have a good mana pool
if that 10SSI makes you realy swing faster
then it is a choice you can make.
I love the helmet on my PvP archer.....heavy X-bow with 50SSI and 184 stamina shoots very very fast and makes big holes into the armor of my opponents