Just finished a playthrough of the mod, and I'm quite happy with it.
The mod does a superb job of giving the player options for building characters in interesting ways. The choice to use each character now implies certain things about how the party needs to be composed and used, exactly as intended. Moreover, the progression from the beginning to the end of the game is exceptionally smooth - I honestly can't say I've ever seen another game pull it off. The only real discontinuity in power was when I got Tifa a particular combination of weapon and relic that doubled her damage output. Other than that, power gains were gradual but noticeable throughout the entire range of the game's progression. I wound up hitting level 99 with my main party almost exactly at the bottom of the Crater, and with the rest of the party by the time I'd finished the level 4 limit quests and the new Emerald WEAPON - perfect timing. I will admit that, after the Icicle area, things started getting relatively easy - there were almost no game overs and little need to adjust my party or equipment to fit a particular battle outside of the optional content, but there were plenty of close calls. For reference, I almost never ran, but I also didn't grind outside of searching for Chocobo breeding materials (which it turns out I didn't need - kudos to Sega for making that sidequest only needed for folks who want to race). I also never had a shortage of gil, especially after the Raid on Midgar; I ended the game with over 5 million. I did tend to set up Tifa with as many Counter Attack and Command Counter + Deathblow materia as I could fit beside whatever else I needed her for, so that might have helped, as she was routinely hitting 3 or 4 times for every time an enemy hit her (more at the end, less at the start).
Balance between characters wasn't quite so perfect - I found Tifa to be overwhelmingly good. Between her access to weapons like Powersoul, an innate ability that synergizes with the easiest way to get the power boost from those weapons, much easier access to her ultimate weapon (due to being able to simply buy one of the ingredients on the Highwind), and a limit break chain that only ever accumulates power since you get to use all of them at once, she just is extremely easy to make very powerful. Maybe other characters have a higher power ceiling, but Tifa just gets to be incredibly awesome very easily. While I do appreciate the addition of fights that require precision in targeting (which make both 4x Cut and her limit breaks serious drawbacks), there just aren't enough of those to get me to give up having her in the party - if it comes to it, I just switch to Deathblows, which her high Dex allows her to land reliably.
The script and plot changes were great. I'm not going to get too into them, but they're rare - and when they happen, they do one of a few things - they give information to the player that they really ought to have in order to help the plot make sense, they correct major blunders in executing the story, or they add some humor that fits neatly into the available context (in this regard, I think NT is superior to Brave New World, a mod for FF6 on this site that NT seems to get compared to a lot). There's one major change that becomes obvious in the midgame, and I think it's a good one to make - the devs of the original game gave some justifications for their choices, but those justifications fall flat once you view the story as a whole. It's a case of the developers only seeing what they were trying to communicate, but failing to realize that it ran against the entire structure of the rest of the plot. Sega takes what I think is the only real way of repairing things, and does it in a way that had me laughing for far longer than it really deserved.
Aside from a few bosses in the Nibelheim area, which I've whined about adequately in chat, I only have one complaint about the mod. Toward the end, it starts to fall prey to some of the same problems as vanilla FF7, and I think they're some of the same problems you set out to fix. Thanks to the existence of materia like Quadra-Magic, Double Cut, W-Summon, and Knights of the Round, battles at the end of the game tend to get pretty samey. At the same time, the frequent use of multiple status effects (while definitely a welcome departure from vanilla) creates a similar need to adhere to particular strategies in all battles. At the end of the game, there were a number of battles that simply demanded a Ribbon, Hades and Ifrit Added Effect on armor, or Resist to deal with, because if you didn't have those you'd be swamped with too many status effects to handle, especially since several of them would take control of a character away from the player. This is a fine requirement to have in a few battles, but by the end of the game it gets stale. Unfortunately, solving the complaint is tough - it requires redesigning the endgame pretty much from the ground up to get rid of effects that bypass the damage cap by hitting multiple times, and replacing the bosses that expect them with encounters like Abyss that demand cleverness from the player instead of brute optimization is not trivial because somebody has to come up with those ideas. When the difficulties of coping with the engine are brought in beside that, I don't know how reasonable it is to hope for something like that.
At any rate, thanks for doing this. By and large, this mod is a strict improvement on vanilla. It introduces great ways to make characters unique, creates a very well-constructed balance paradigm, gives reasons to use every character (especially Tifa), and does some great work with the script. It's also (mostly) compatible with graphics mods for the game, which improved my experience dramatically. It doesn't completely solve all of vanilla's problems, but the ones it doesn't fix it definitely forestalls.
