I highly doubt we will see SS and Magi revisited before the Balance patch (which is rumored to come after sets for DH and Necro are released), but if they do and get close to what you suggested then TV with 15xx-16xx % per head will be fine.
However if they don’t touch SS and Magi we need at least 2000% per head on 6pc bonus (and I would include another skill on 6pc as well, like arcane orb, twister or mirror images).
Problem with set is that you simply can’t fit in all the items you need like on LoD. You need Tasker’s. Mantle of Channeling would be nice, but can’t fit in. This means you can’t use SG / IC (even if you would use invigorating gem and drop IC). You need to use both Magistrate and Serpent since they are only legendaries that affect hydra dmg.
You have to cube RoRG to wear 1 piece of your choice (between helm and gloves). So you can’t have both Flavor and Squirt’s. Traveler’s would been nice but since we have no way to become CC immune with the set, you can’t rely on channeling (standing still). You can’t use CC cause there’s no CD that you really need to lower being a channel build, and RcR is not needed as you will run the belt to reduce your preferred channeling spell resource cost.
If we didn’t had to channel, we would had some great options for S20 theme in the cube (like running EB for more toughness offhand, EF for some sweet AS buff to pets etc).
So pretty much we’re forced into channeling because only 2 supporting legendaries buff the main damage skill, and then we rely completely on 6pc bonus to do the heavy lifting.
Am very curious on your TV report (maybe a vid too? ^^). Currently am doing GR110 at 1650 para using arcane hydra and BH spellsteal. I can’t stand frost hydra their range is so short, that anything that moves a lot on screen is a nightmare to fight (teleporters, flyers, RG). No augs, lvl 112 gems (trapped, pet and channeling - leveled them with the set from rank 25), only DW is ancient, rest normal gear (but I have a 99% bracer for shield, and 79% karini so those are good rolls on important pieces).
The sad thing is that even with the belt that reduces channeling cost by 65%, you still need on source AP on crit, or you will run out of AP when you need to manually re-cast your black hole, reposition hydras and channel (even worse if you get speed pylon). So getting both 15% hydra and 3-4AP / crit, on top of a good ChC roll and int + vit will be quite the sight (you need vit to get bigger shields because you are not as tanky as Vyr’s or LoD channeling builds, at least not at my paragon).
Meanwhile my LoD meteor shower can do 120 in about 8m. I highly doubt that simply getting ancients and augmenting with rank 100 gems will get VT past 115 at same paragon.
