normaly a good craft has more physical damage than the Emberstorm , also the SoR proc deals better weapon damage compared to most of the procs of that type , combined also with the benefits of debuff (12% ctc Flury of Javelins proc is also worth a try ) . If you are using Spellbind as often as possible , then the SoR debuff is not so mandatory , while all is left to compare are the procs .
Cataclysm is dealing decent fire damage if you got some energy investments and %fire spell damage/spell pierce when you use it as a caster . For a weapon damage build that does not invest into boosting elemental spells , the only good thing about that proc is that it is dealing quite a lot of damage if the opponents are close to the place it procs (more fireballs hit the same target) .
overall , i would not trade a good craft for Emberstorm , but you may try it for the flavour and decide yourself if it suits you or not .
good luck !
i've been away from gaming since more than a week ago as i had a lot of work to do moving to my brand new appartment and the busy days may continue a bit more (there is still stuff to be put at place ) . i will probably proceed with the updates to the remaining miniguides in about 2-3 days .