zrx ignition advacers

Hi all
Can anyone give me the drum on the ELS ignition advancers , iv,e been thing of getting one for a while but want to be sure its the right thing for my Rex, what are the pros and cons i suppose is the question i,m asking.
My Rex is basicly stock except Remus slipon can and Factory pro stage 3 jet, kit my main concern is not to lose any of the great that it has.
Thanks Neale.
Can anyone give me the drum on the ELS ignition advancers , iv,e been thing of getting one for a while but want to be sure its the right thing for my Rex, what are the pros and cons i suppose is the question i,m asking.
My Rex is basicly stock except Remus slipon can and Factory pro stage 3 jet, kit my main concern is not to lose any of the great that it has.
Thanks Neale.