This is a 30 min montage of the spell Vortex before it was ruined by GGG.
TLDR: Vortex is ruined for self cast or cast on X. Use Ice Nova or Melee/CoC. (has larger AoE - cast speed remains unaffected). Expect that GGG will make Ice Nova just as worthless in upcoming patches.

* This version of Vortex has been retired. Vortex is now completely worthless and ruined, exactly as I predicted. I lost 40k dps and 4 casts per second, and at lvl22 Vortex has only 84% cooldown. Can only cast once per second (compared to 4.9 casts per second previously). Also, instead of being able to hold down a mouse click to use Vortex, you must now click over and over and over again. Vortex has been changed in Betrayal, and no longer provides "an additional 40% damage when cast on frostbolt". Vortex also has a 1.8 second cool down now, although you can cast while moving. The cooldown, at lvl22, will amount to about 1.17 seconds. You can get another 25-35% with boots and belt. GGG will need to add additional helmet enchants for Vortex cooldown or cooldown in general on different types of gear. You could also try a lvl 4 corrupt empower, inside of a double corrupt + gems. Summary: "I decided to move away from "cast on X" and frostbolt interaction and focus on self cast and fighting bosses. I can't imagine you'll be able to match the casting speed seen here in the future. I made this montage to compare to the reworked version.

*UPDATE: It turns out there is absolutely no comparison (https://www.youtube.com/watch?v=IcKHWVcyVY4). This spell was ruined by all the people that complained without ever taking it far enough to get it to work." ** Future Suggestion ** Revert Vortex back to v3.4.5 of the gem and allow players to cast while moving. Add AoE. Add an additional 40% damage when self casting. Put Vortex helmet enchantment damage modifiers back in the game. If you don't revert the spell and it remains with a cooldown forever, then add some actual cooldown reduction gear into the game.

*UPDATE 2: The only way to use Vortex now is via a melee character with Cast On Crit or Poet's Pen type mechanic. Ridiculous development decision.

Skills used:
- Vortex v.3.4.5
- Righteous Fire
- Frost Bomb [CwDT] - Ice Nova [CwDT] - Blade Vortex [CwDT] - Flame Dash

Timeline:
50s - Mapping
4m28s - Defense
7m50s - Hall Of Grandmaster
9m52s - TheSpiderQueenbyDemi PvP
10m32s - Izaro / Uber Lab
11m37s- Atziri / Uber Atziri
13m25s - Boss Fights
26m48s - Elder & Saving Shaper

Special Thanks to RedsDead @ NOGG Society
Special Thanks to Demi
Music: http://soundcloud.com/kijostyle/