Jro, while I'm happy that you took the plunge and are trying this out, I think we have a long way to go before this becomes viable for the members for the forum- at least viable from a perspective of matching up with what a 2stone can do.
There's the obvious similarities (I really can't believe how non-litigious Willard is), but, there also seems to be some differences. It's been a while and my memory is both hazy, and, over the years, my eye has gotten more discerning when it comes to detecting Neapolitan traits, so I can't say with absolutely certainty that a 2stone can do 60-90 second bakes with Neapolitan dough, but, if it can, it only just can. Any deviations from the 2stone model will very likely move it's capabilities outside of that realm. Potential deviations include.
1. Hearth material.
Fibrament's low conductivity is critical to the 2stone thermodynamics. Since a Fibrament stone, even wholesale, is most likely not less than $50, I highly doubt they'd be be using $100 worth of Fibrament stones in a device that retails for less than $400.
As soon as you get into a cordierite stone, the bottom will brown far faster. If you end up, because of the conductivity of the fibrament, having to dial down the hearth to 750-ish temps to hit 60-90 second bakes, then that means that you'll only hit 900ish for the ceiling and that probably won't cut it.
Now, you can always swap out the stone for fibrament, and/or possibly add some deflection by added spaces (washers) between the steel and stone, but the stone material is something to be aware of.
2. Flame position.
Willard keeps playing with the 2stone configuration, so I'm not exactly sure where the flame is in regard to the stone, but the photo of the blackstone shows the hottest (bluest) part of the flame directly under the stone. This could easily translate into an extremely unevenly heated stone.
Jro, next time you pre-heat this, could you take readings from the center and edge of the stone?
Again, this is another instance of not knowing exactly where the 2stone is presently, but I believe Willard has a steel sheet between the bottom/side of the stone and the flame, forcing more heat to the ceiling.
The price is excellent and, on outward appearance, this seems pretty 2stone-ish, but, at the same time, there's a lot less expensive methods to do NY style bakes, so the only way this becomes an amazing deal is if it can do NP, and we're a ways away from confirming that.