Have been experimenting alot with the whirlwind barbarian speed build since the start of season 13, and have come up with a solid build to push T13 speeds and GR60s with ~800 paragon.
Have done as fast as 1.2 minute clears, with good mobs and good range, have added a video to showcase a few standard runs.
-Just a sidenote, I am not a professional, and as you can tell in the video, I make many mistakes, but still manage to finish with above average times.
This build has great speed, and enough damage to one-shot virtually everything on screen, with elites being the exception.
This build uses the two sets:
-Wrath of the Wastes for damage reduction, and massive increased damage to Whirlwind.
-Bul'Katho's Oath to increase fury generation, and move/attack speed.
We use a hellfire amulet, for a nice 5th passive, preferably Berserker Rage, but other viable options are Brawler, Nerves of Steel, or Pound of Flesh.
We use Strongarm Bracers in conjunction with Ignore Pain for a knockback CC aswell as (up to) 30% increased damage.
Pride of Casseus to extend Ignore Pain so we get permanent uptime.
Obsidian Ring of the Zodiac to reduce the cooldown of Wrath of the Berserker (and Ignore pain) to get permanent uptime.
We have Furnace in the weapon slot in the cube, (and SoJ) to make up for the builds lacking elite damage, mantle of channelling in the armor slot for extra damage and toughness, and preferably Skull Grasp in the ring slot to get that perfect 400% whirlwind damage buff.
If you want more general damage:
-Replace SoJ with Ring of Royal Grandeur, put Hexxing Pants in the cube, and replace Weapons Master passive with Brawler.
Note:You will lose the % damage to elites and physical damage increase, though.
If you want more general recovery:
-Replace Ignore Pain rune with Ignorance is Bliss, and replace Sprint rune with Gangway if you still want to proc Strongarm Bracers.
Note: you will be a little bit slower this way, but recover more life per fury spent when dealing damage with whirlwind.
If you're having trouble generating fury:
-Switch out Whirlwind rune to Wind Shear, and change %Skill Damage to Lightning.
Note: You lose the damage bonus applied to the 6 set applied rune (Dust Devils) but you no longer have any fury generating problems.
If you're having trouble with Cooldown Reduction:
-Replace The Furnace in the cube with In-geom.
Note:You lose %Elite Damage, but you should no longer have any problems with keeping WotB and IP up if you're killing atleast one elite pack every cooldown cycle.
If you're in a group:
Swap out Ignore Pain rune for Mob Rule, and replace Strongarm Bracers with Nemesis Bracers.
If you're over 1000 Paragon and want to gold farm:
Replace SoJ with Avarice Band, and replace Gogok of Swiftness with Boon of the Hoarder.
Replace Pride of Casseus with Goldwrap, and replace Ignore Pain for Threatening Shout with Falter rune.
Replace War Cry rune with Charge! and Battle Rage rune with Ferocity.
Note: This build alteration gives you all the toughness you need with the classic Goldwrap/BotH/Avarice Band combo, so we instead replace several damage mitigation abilities with either more damage, or more speed. From my testing, this build does slightly less damage than the standard one, and would be fine farming TX-T12 if under 1000 paragon.
Just a final note, I have not taken this build from anyone specific, I have altered and added to several other builds and experimented with several different adaptations, and wanted to share the information with all of you to hopefully save you some time, and give you a decent speed build that doesn't involve Furious Charge
If you have any questions or comments about this build, feel free to either leave me a comment below, or come and ask me live @ twitch.tv/karnif3x