I concur with Coaster above, today really was brilliant! For a preview day, I gotta give credit to the park here as I was honestly surprised by how well things were being run and the availability of the attractions for guests, especially when Stealth unexpectedly opened in the early afternoon. I'd go as far as to say this has been one of the best preview events the park has held yet.
All coasters minus WD were running full capacity, including Colossus on two trains and Tidal Wave on two boats which is something rarely seen these days! The staff running the coasters were on fire too with frequent and fast dispatch times. No messing around or delays this visit anywhere across any ride. Staff were friendly and cooperative when DBGT broke down and all of them seem enthused, which is a promising start to the season.
Probably the most surprising thing for me was walking into a park where every minute between 10am - 5pm, the coasters did not remove any trains on their circuits due to small queues later in the day, which has become a terrible habit of this park lately. Instead, by 4pm, I was riding a train on Colossus with only 6 guests and loads of empty ones. Same for Inferno too. This is what I like to see!
As for the changes and things I noticed across the park, there are some questionable cosmetic changes made inside the dome I really don't think highly of, especially given it's just black walls everywhere now and PVC posters in front of the store instead of a glass display window as an example. It looks so incredibly dull in there without the old theming anymore and no massive widescreen projector will ever excuse the decision to do this. Also, there were some areas of the park which clearly weren't looked over properly during the winter, as the LED lighting rigs from Fright Nights are still standing next to Tidal Wave, Loggers Leap and IAC. Why are they still standing? It looks really lazy.
Colossus in-person looks awful with the land filled in under the vertical loop. They could have at least turfed the ground with some grass or plants couldn't they? Least the original audio was back on it today which was great to hear! It honestly suits the coaster so much better than the IMAscore version.
Swarm's station was also quite bad, as whilst they painted the steel supports after removing all the cladding surrounding them, they didn't paint the footers right down to the ground and as a result, bare silver metal is still visible near the floor on all the supports. It looks really bad and like a botch job.
But most of all, my biggest concern about what I saw from today was a seriously worrying lack of upkeep with their audio and SFX, because it was incredibly inconsistent in some areas and many effects have not been fixed since the end of last season. This is something I have noticed Chessington and Alton Towers are also suffering from currently so it's not unique just to Thorpe.
Here is a long list of every little observation I made from today for each ride. Used spoiler tags to keep this post from getting too long: