For PvP, Nrg/Elec is the best choice. Why? Lets take a look at the Primaries and Secondaries.
- Energy or Electric Melee
Almost every attack from the Nrg set is a single target, and Elec has some cone attacks. Obviously, the damage and the number of targets of an attack influence its endurance cost, so when you attack with a cone to hit only one opponent in PvP, you are wasting End. So, in this aspect, Nrg is better. PvP is about single target burst damage.
Lets look at the side effects: Nrg has a Disoriemt component, and Electric has End Drain. Elec's End Drain by itself is not enough to make your opponent's Endurance run off. But the Disorient component is gold in PvP.
IMO, Elec Melee is very good for PvE, specially with Elec Armor as Lightning Field also drains endurance over time and it has Power Sink. Nrg Armor has End Drain, so I can say theres some synergy between the sets.
- Energy and Electric Armor
Both have some cool mez protection, like end drain, tp fow, etc. And they dont require the Leaping Pool for KB protection, like Fire or Dark.
Keep in mind that every time you choose Energy Armor, you are choosing odds over reliability. Nrg is about defense, reducing the chance the enemy has of hitting you. That means they will hit you less, but you'll take full damage when they manage it. Elec Armor is a set based on resistance, so you'll always know how much you can take before hitting the floor.
Yes, the enemies' attacks will also miss sometimes if you have Elec, but keep in mind that mobs cant slot their attacks! In PvP, players have (or are supposed to) at least 2 ACC in each attack, along with access to powers like Build Up, Rage, Tactics, Focused Accuracy, etc. So, no matter how good the defense provided from Nrg is, you'll get hit. A lot. And so will the guy with Elec Armor, but he will stand longer because of his resists.
Also, Elec Armor provides resistance to Psi when Nrg has no defense against this type of damage.
- Conclusion
Energy Melee/Electric Armor is, in comparison to Elec/Nrg, better for PvP. I remember a toon called Clint Thrust from a while back who had these sets and was feared in RV.
If you still have any questions, just ask.
[b] thanks mate, that helps alot 
Wow, I did't even remember this topic anymore hehe
But you are welcome!
Im lvling an EM/inv toon atm, and its good that u can hit dull pain and get an 800hp heal; especially when u will be loosing health (even against the weakest mobs) in a long fight when using energy transfer. Dull pain does kindof counter the health point loss from ur best attack; so bare that in mind.
However what u would lose in ease of use from /inv with lightening reflexes u would have even faster recharge of your big hitting attacks which cant be bad. Id be inclind to stick with my original choice however; u wont get anywhere if u keep changing ur mind and rerolling. I waited till lv 50 to start a new brute which could do damage which is what DM lacks.
Ok im having some troubles with En and Elec, i like both sets alot primary and secondry, i have a lvl 20 En/En brute and find it amazing can do almost anything with him. The other daay i thought about trying out Elec/Elec so i got this one up to lvl 8, i find both really cool, but dont fancy just yet of switching between toons all the time so, i wonderd what do you guys think about either a Elec/En or En/Elec id like to use it for PvP but im guessing any player can be good at pve just got to know the right things, soooo Which set where?? En/Elec or Elec/En hmmm maybe evan stick with En/En or my Elec/Elec, just wanted some of your opions on what you like and dislike abouth the sets?
Any help would be loved