I use NAM in the studio, because IMHO it's the best sounding option available. And because I have a very nice interface - nicer than what you get with standalone hardware - this inconsistency works in my favour. If you see my point.
The guy who make the best NAM captures also recently updated his interface to a much nicer one and the results are noticeably better again.
If Stadium can match what I'm getting on my studio with NAM, it'll be a no brainier. Or if it can play the hyper accurate captures, again, no brainier.
But otherwise I'll just stick with the Helix Floor for live and NAM for the studio.
Tonex, BTW, sounds miles worse than the best NAM captures, as does the Kemper. I think the "cost" of NAM is the time it takes finding good captures. But that's a lot easier now that the hyper accurate captures exist.
And since the guy making those is widely sharing his method, it's just a matrer of time before more people hop on board and fill in the gaps.