Thats the first time EVER that i have seen a ladder item with +5 to all skills. If anything a sorc can use it to cast her defensive spells, then switch back to what she was using.
That is really good. Just think if it were perfect (-15 to all of those things=PWN!) Useful for a trapsin too because of the +skills and - to light resist.
IMHO I would think that sacrificing 1 or 2 skills and go with Fathom and Lidless or something to that effect, if you need the resistance for hell(on a sorc obviously) I would think that a little less damage would'nt outweigh dying to whatever elements should be thrown at you, but definetly good; faster cast aswell