I just want to share some of my expieriences with the new TNT.
I played and built the TNT version, that won the Heidelberg tournament.
Yes, Jacob Orlove is right, the Duplicants and Uktabis are a metagame choice.
In Heidelberg a lot of Aggro-Decks are played. Out of 20-25 players there are often 4 Workshop Decks, 2 Hulk, 2 Sligh, some Mono Black, 2-3 Elves, 2 Keeper, 1-2 Combo, 1 "Green-white-Anti-Artifact-Deck" (Serenity), 1 Bazaar Animator, 1 Vengeur Masque and sometimes 1 White Weenie and some random Decks.
That is the reason for the Duplicants, Uktabis, Solemn Simulacrums and Artifact Mutations.
Duplicant:
Against Psychatog, Acroma, Dreadnaughts, Nantuku Shades, flying Arrogant Wurms and other Threats the Duplicants are golden.
And with workshops and/or the extra lands from Simulacrum I am able to hardcast it very early.
In most cases Duplicant (as well as Triskelion) is faster than Masticore, because you don't have enough mana to deal enough damage to bigger creatures.
Solemn Simulacrum:
The Solemn Simulacrums stabilize the Mana Base of the Deck.
Even with 29 mana Sources in my TNT some Wastelands, Sinkholes and Powder Kegs of an opponents Suicide Deck cause Mana screw.
Most Decks are able to kill your first creature, so a first turn Su-Chi will resultin 4 Mana burn damage. Followed by wasteland you will only have 2 Mana in your next turn. one Mox and a land you play in that next turn.
It is also better suited to sacrifice for an opponents Smokestack than a Su-Chi.
And when your opponent has an active welder you don't want to have a Su-Chi in your grave...
Solemn Simulacrum gives you an early Chumb Blocker with card advantage in an Aggro metagame.
And with Welders you can use it as a draw engine as an option.
(that also produces mana and thins out the library)
After welding the Simulacrum it is quite easy to hardcast Duplicant or Triskelion without a Workshop on the table.
With a first turn Simulacrum you have most of the time 6 Mana in your next turn.
I want to play a Simulacrum as early as posible, that is why I am playing 4.
Often I was able to play an other threat after the Simulacrum got blocked to death, welded or otherwise killed because of the carddrawing effect.
In the tournament before I was playing against:
1. round: Ductape
2: round: Ductape
3. round: TNT
...
(myself also playing TNT)
So, I can say that the Heidelberg metagame is Workshop and Aggro infested.
Uktabi Orangutan:
Shaman kills no Dreadnaughts Smokestaks, Su-Chis, Triskelions and Juggernauts and is often to slow to kill a Mask.
Blood Moon:
Against some decks Blood Moon just wins the game alone.
Hulk, Keeper and other decks playing fetch- and dual-lands
This deck is so strong against aggro, that it can afford these 4 situational slots.
I didn't maindeck Chalice of the void because it is not effective in the matchup and against Sligh I don't really need it. But it is nice to side them in for the Blood Moons
Price of Progress and Wasteland is the reason why I am playing the Deck with only 2 colors.
So much for the Heidelberg metagame.
I think I would change the deck and sideboard, when playing in the combo-infested Dülmen metagame.
(Perhaps I would play maindeck Tormods Crypt.

TNT is consistent and flexible.
It is not as easily hatet as other decks
(Blood Moon, Planar Void, Tormods, Crypt, Stifle, Swords, Disenchant/Naturalize, Wastelands...)
Other workshop decks (charbelcher welder mud) have problems with Serenity and other artifacthate, which is played in Heidelberg.
Madness has problems against an early Blood Moon and Pernicious Deed (which is played in a lot of Suicide decks).
And Madness has lost Lion's Eye Diamond.
Dragon is very strong, but also heavily played, so a lot of people are prepared for it.
My little experience with Mask decks is, that the mana base is quite weak. Most decks I am playing against have 5 Strips and Shamans, Sinkholes or Stifles.
Mask decks are not so strong without the mask, but TNT does not depend so much ob Survival or Workshop.
Sorry for my english, I hope this post was understandable.
Marcus