The Chroma does not have many innovations compared to its predecessor. Both have 2500 ANSI lumens, pixel shift 4k and HDR10. There are first videos on YouTube comparing the two. The Chroma has ALP4.0 and the Triple Laser, which is why the Chroma has slightly better colours and black levels. Only you can decide whether the surcharge is worth it.
I think the price of the 4K UST will also come down a little soon.
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