Overload - GREAT Ultimate, each hit does almost as much as a crystal shard and the AoE version of it is just OP, great for single target and AoE scenarios, has saved my life a loot.
Mages Fury - Great for Dungeons or mobs with high hp, its an extremely good execution spell doing 5 times more DPS than Crystal Shard when enemy is under 20% hp.
Lightning Form - It was good in Cyrodiil in lower levels but since then it has been replaced with Bolt Escape on my end. Spell Resistance is capped at 50% reduction so it could be good in some scenarios but not enough imo.
Lightning Splash - People are saying that its a good AoE spell, personally I use Impulse from the destruction staff. I cant say much about this.
Surge - This one in my opinion is the weak point, the added weapon damage from Surge isnt enough, using Crystal Shard with a Dark Exchange combination does about 50% more dps than this. Its lacking too much, not worth it.
Bolt Escape - My favorite spell, it outspeeds a horse, its fun to use and its a great retreat spell. The morphed version can spawn a ball of lightning that makes you immune against Spell Projectiles for 6.5 seconds. Thats OP, all you have to do is cast the spell every 6.5 seconds and you are immune against casters (pretty much).. too bad its bugged atm.
This is my intake on the spells, Personally, I use 3/6 of the spells in my actionbar at this moment.
Surge - This one in my opinion is the weak point,