I've been on Nemesis Reborn today so I can offer up thoughts that I'm sure aren't original at this point.
Firstly I'd like to say how I like that Forbidden Valley is much more alive. There's much more going on, and the Phalanx crew and the "Nemesis does have feelings" people were a fun addition. I expect they won't keep the people out and about in the area forever.
It was a while before I actually got on it - I beelined straight there only to be told that it wasn't open, or testing, and they had no idea when it would be open and suggested that I return, which was a very bad start. I had a brief chat with a Phalanx girl who told me Reborn was mainly different because it was smoother which I was dubious about after what I'd heard. Anyway I couldn't go on it right away. Nor Wickerman as that wasn't open either. By the time I'd been to X Sector, both rides were open, so I was able to finally go on Reborn. Overall I wasn't too impressed with operations - while everything did open eventually, it was a bad start and even then operations across the park felt very slow. Oblivion was stacking a lot and I had to wait 20 minutes for it, which is longer than I've ever waited for that. But I'm getting off topic.
The queue line is interesting - it's a very good queue line because of all the vantage points from where you can see the track and trains go round, but I did feel it was more cut off from the ride than the original version. The original queue had the feeling you were in the ride almost, which was great. It seems like only the very end bit was the same as before, though I might be wrong. If anyone's ever played Pokemon Black and White and then gone to their sequels, it's like how Victory Road is almost completely different except for the last two rooms. As for the music, I kind of want to say the original music was better, but that it wouldn't fit in with the new theming elements so I do at least appreciate them not just keeping everything the same. I'd say the same about the queue line.
The overall theming and station are great - but I wasn't a fan of the assigned seating and how there's no longer a front row queue. Assigned seating seemed to be all over Alton Towers today which is disappointing. So unfortunately I didn't get a front row ride. But I did on Oblivion and Smiler by complete chance, but anyway.
As for the ride itself, it feels very much the same as before, but it is weirdly rougher than the original. Not brutally rough, but it certainly has a rattle. The mist by the zero-g roll and around the second corkscrew were a nice touch. I got 2 rides in, one on row 2 on the right, and then one on 3 on the left. The first one felt weirdly not as intense as I remembered it. I guess the ride had warmed up by the afternoon, as the second on row 3 was much better than the first. A lot more aggressive like the Nemesis I remember. It's still a great ride, but I think my trip to Liseberg last year raised the bar as it made Alton's lineup feel that much worse. Or maybe I've just done Alton Towers to death, who can say.
Overall I'd say the updates were positive, but I am uncertain as to whether it'll get really rough over the next couple of years and become flatly worse than the original ride, which I felt was fairly smooth even in 2022. The paint scheme will also probably look worse - it'll go grey like Smiler. Not going to lie, the rattle concerns me a lot.