One UI doesn't use that much more space compared to other skins if you judge by the size of the super partition. Unfortunately, ArsTechnica jumped the gun on the topic without doing proper research.
I'll edit this comment later with a list of pre-installed apps on the US unlocked model later.
Edit: List of pre-installed apps on the (* denotes it can be uninstalled)
-In the Google folder: Google, Chrome, Gmail, Maps, YouTube, Drive*, Google TV*, Meet. And Photos*.
-In the Microsoft folder: LinkedIn*, Microsoft 365*, OneDrive, and Outlook*.
-In the Samsung folder: Find*, Health*, Members*, Messages, My Files, PENUP*, Shop Samsung*, SmartThings*, TV*, Voice Recorder*, Wearable*.
Apps outside the folder: Assistant, Calculator*, Calendar*, Camera, Clock*, Contacts, Facebook*, Gallery, Gaming Hub*, Global Goals*, Internet, Messages, Netflix*, News, Notes*, Phone, Play Store, Settings, Spotify*, Store, Tips*, Wallet*, and YouTube Music*.
Both materials feel cool to the touch when initially held. I'd say the titanium is a bit more grippier which might be relevant if you like to use your phone without a case.
The colours are matched more on the back and frame for the S24/+ compared to the S24U.