I don't find blizzard especially impressive post enhancement diversification. It's low enough damage with only 3 slots that mobs can easily run out of it before they die. It's damage is unaffected by any buffs, which includes aim and build up, so 3 damage SOs worth is what you're getting - not that tremendous really.
If you are going to use it then I'd suggest combining it with a slow. Either Ice Storm (slotted with 3 slows, you could also add 3 damage to that) from the Ice primary, or if you've got ice secondary then Shiver (slotted 2 accuracy - it really needs them - and 2 slows). Dropping one of those and then blizzard will generally mean that your mobs will stay in for long enough to take a reasonable amount of damage. You could even slot blizzard with 3 slows as well as 3 damage which makes a fairly lethal combination.
If you use it without some sort of slow you're likely to kill little except yourself and probably annoy any tanker you play with quite a bit 
Overall I don't personally rate it as worth the endurance penalties. I very much went for the single target/control angle on my ice/ice and spending that many slots on it didn't fit with what I was after - Ice has a lot of other good powers and I wanted those more. It can still be used effectively though.
Aye is why I was wondering, really wasnt sure about getting it, as am also very single target. Think I will pick up a pool power instead.
I used to like Blizzard, before ED.It appears to have lost alot of its power since ED. I used to be able to cast it on reds and orange mobs and practally take them out. Since ED i tried it out on a group of yellow con mobs and it never killed them out right , like i was expecting it to. I normally use shiver than hit them with blizzard.
the knockdown is still handy, but blizzard the power has been gutted since ED, in fact my whole ice blaster is alot weaker. (Cant even one shot an even con mob any more with build up + bitter ice bolt) 
@Snow.
Defiant: Snow + many other alts
Arc ID 61069
Well in a recent Carnie mission, against yellow/orange mobs, my Blizzard still wiped out a group of about 10, and i only have 3 lvl50 damage so's, and 3 end reduc in the power!
Keeping Blizzard, reguardless of ED, it's still a worthwhile power, and still "nukes"! 
How does EndRed work in a nuke? It drains all end so what is the benefit of endred?
It makes it cost less endurance to activate. Blizzard has an activation cost of ~ 20. I can't remember the exact number offhand, but that's fairly close. Endurance reducers make absolutely no difference to the total drain and minus recovery.
i re-sloted mine with 3 recharges so i may now do half the damage but i can use it more often
[ QUOTE ]
How does EndRed work in a nuke? It drains all end so what is the benefit of endred?
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It Reduces the End cost of the powers usage, has nothing to do with the End Drain AFTER the usage.
That way even with a tiny amount of end left, i can still activate Blizzard!
Doh
It's been a while since I had my ice out and about, and my brain grinds when I try to put it in gear 
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Anyone had a play with this power? Just wondering if it is any good? Would welcome any advice/comments folks have.
Ta