I can't help you on the Primary as I've never played it but I can tell you that /Elec as a secondary gets depressingly weak after about level 20ish. You'll need about a dozen blasts just to take down an even con lieutenant. On the plus side, you get a nice hold and a pet with the set which goes very well with controllery Primaries.
As has been mentioned on the Defender boards recently endurance drain is a real all or nothing strategy. You'll need triple slotted Short Circuit and Power Sink from the epics to really use it as an attack. That said, in a long fight (say with an Elite Boss or an AV) it can work really well.
@Dante EU - Union Roleplayer and Altisis Victim
The Militia: Union RP Supergroup - www.themilitia.org.uk
Anyone else?
Thanks Dante 
I have a storm/elec at level 35, its very nice..
when solo I end to use Aim+Zapp (with interrupt enhancements) as a starter which helps a bit with the damage. Then, when I get a team I simply switch it with O2 boost for that button in the tray as zapp is a bit slow to use in teams (but if you have a team your own personal dps is a lesser concern)
You get a free stealth with steamy mist, which is nice, since you can get pretty close to enemy mob groups and not get aggro prematurely, and the icing on the cake is that same goes for that overeager "squishy AT" newbie while waiting for the tank to catch up from behind.
Weakness? yes, pre-stamina in the late teens to early twenties its very endurance draining (somehow the Devs think that the drain part of elec should make up for it, it doesn't..) but another added bonus is that if you are safe from aggro you can get back endurance when resting and still keep alot of toggles running and remain helpful to the team.
Defending with Storm is said to be "controllery" or "chaotic".. that is true. A bad team can have problems with your chaotic defending, while a good team wont just manage, but probably enjoy it as well.
UNION
Officer Cuffz lvl 50 Inv/Nrg Tank
Badge lvl 50 dwarf/human Peacebringer
Dark Air lvl 50 Ice/Cold Corruptor
Ayre lvl 50 Storm/Elec Defender
Total Cat: @Officer Cuffz
"When I say interview, I mean engage in combat and defeat..." -Laura Brunetti, on how to deal with Warriors.
Chaos:
1. a state of utter confusion or disorder; a total lack of organization or order.
2. any confused, disorderly mass.
A bad stormie will bring it upon the team and a good one will bring it upon the enemy. Sometimes people need to get to know each other and get used to each other progressively.
I made the key thing between my storm and elec side about the end drain and planned to get elec mastery. Storm is rather endurance unfriendly so a mix of sap and replenish is nice especially as storm has -end in it anyway from lightning storm.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
So it's a hard primary to play?
Depends on the person and who they team with. The highest level of storm i have played is 40. If the team is in good health your doing well, if the team is in bad health your not doing well "as a team" and some tactical meet in the middle is preferable. There is a time and place for powers, they can be used to positively combine with other peoples or act against them. Random actions can have a seriously bad effect. Galing barely touched mobs into more and more mobs is in mission griefing for one.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
Ahhh so like all powers, there's a tim and place. Thanks Shannon
Storm is one of those power sets that can be spectacularly good if played well and spectacularly unhelpful (to the point where your team would do better if you were not there) if played badly.
I thought elec was a pretty weak secondary for storm to be honest. I enjoyed my storm/dark a lot more and I would imagine that storm/sonic would be great too. Elec is a bit.. meh to be honest.
I have a lvl 47 storm/rad and my experience is that first of all,these two powersets work well together,and secondly that what previous posters have said about the chaos factor is absolutely true,if you know what you´re doing you´ll love it and so will the team(except some tanks hehe)but the margin for error is sometimes quite narrow,but generally i would strongly recommend storm,i cant see myself playing anything else at the moment,and also with hurricane and lightning storm and freezing rain you´re the undisputed king of the Terror Volta respecs
Rolled a Storm/Elec defender. Was going to do a pure elec Blaster but wanted something a bit different.
What are these powersets' weaknesses/strengths?