Tempest Rush is very fun build but it's not for everyone indeed. It's not as strong as Raiment Gen monk or as fast as Bellwuko/LTK monk of cause, but absolutely viable.
What have changed in patch 2.6.1?
1) Balance and Cesar's Memento were buffed
2) Sunwuko 6pc was reworked, Kyoshiro's Soul not needed anymore.
3) Dual wielding instead of two-hander. Furnace dropped.
4) As a result = spirit cost per second increased from 36 to around 49 and now we are not channeling for "free" with OROTZ.
5) It is not uncommon to mess up cooldowns and drop stacks now and then, unfortunately because of the increased spirit costs.
6) Much harder to play now as you need to watch your cooldowns more closely as well as stack RCR and CDR. But much higher damage
7) As annoying as before to get fucked by Vortex, Wormhole, Jailer, Knockbacks, Nightmarish..
So what i enjoy about the build?
1) It can one-shot elites in 1 COE rotation (in GR85+) if you execute it properly.
2) It's the only channelling monk build
3) It actually requires more skill than for any other monk build out there (IMHO)
4) You can speedfarm T13 in AFK mode like a WW barb.
What are the problems?
1) Squishiness. 3 layers of damage reduction required to survive GR90+
2) Lack of "instant" damage compared to other builds
3) Lack of speed (you can use Dash of cause, but you lose all TR stacks, and you need to channel for a longest time possible for max damage)
4) All mob attacks or elite affixes that stop channelling/knockback = WASTE OF TIME/DPS LOSS. These are Jailer, Knockback, Vortex, Wormhole, Nightmarish
5) Any maps that have doors you need to manually open = leave the game.
6) Damn hard to execute everything properly
So how do you play?
1) Press Sweping Wind once. Get 10 stacks. Start rushing. ALWAYS WATCH SW stacks.
2) When you a near elite--> just when COLD COE rotation rolls in -> immidiately cast Blinding Flash and then immidiately DOUBLE CLICK (or unpress) Left Mouse Button (where your TR is). If you had a lot of stacks = elite will explode with all mobs around. Keep in mind though that explosion area is just 15 yards and it's pretty close. It's much easier to one-shot yellow elites than blue champions packs for that reason.You must absoilutely be AS NEAR TO ELITE AS POSSIBLE.
3) Start building TR stacks again, you can cast Blinding Flash/Dash in density 1-2 more times (depending on your CDR/cooldowns) before a new COLD COE rotation rolls in. Make sure you have you Blinding Flash ready before that!
4) Always refresh your Epiphany and Mystic Ally to have full spirit!
For dps you can use Sieze the Initiative instead of Harmony (around 25% more damage but TR spirit cost will increase 25%).
For damage reduction: Crippling Light. Faith in the Light is only 7% more damage because it's additive (not 29%).
Also Near Death Experience is an option of cause.
More important info:
1) Obisidian Ring procs faster with PE stacks, but PE stacks increase your spirit cost of TR by around 25% as well.
2) Pain Enhancer will give you much more damage than Taeguk. At 7 PE stacks it already outdamages Taeguk, but as i said PE will also increase the spirit cost of TR, and it will be a very big problem to keep spirit up.
2) With Epiphany, 2 Allies and Inner Storm you will be replenishing 36 spirit per second. But if you increase your attack speed with Seize the Initiative or PE stacks = you will start losing spirit really fast.
3) Any maps like Corvus or Act 5 when you need to OPEN DOORS = Just leave the damn game lol. Also mobs with knockbacks, Vortex or Jailer will stop you from channelling and must be avoided (or skipped completely). Invigorating gem will greatly help with Knockbacks and Jailer.
4) Speed Pylon will drain your Spirit VERY FAST and also cause stuttering, so DON'T TAKE IT!
The build can clear 100+ but it requires quite a tonn of fishing at my paragon. I cleared GR98 without a big problem though. Had some decent attempts at GR100 as well.
GR98 CLEAR: https://youtu.be/ERYujQc_Rn0