With OLED, each individual pixel illuminates itself, whereas here with LED-illuminated LCD technology, the screen is divided into 118 or so dimming zones, which can lead to light bleeding when the picture content is unfavourable. The bottom line is that OLED is superior. I bought this 75SM9900 myself some time ago and use it as a PC screen in 8K. LCD is better for that. This one also has a nano-coating for better colour purity.
Unfortunately, we do not have this item on display in any of our branches as we are currently prioritising other items in our display. Sorry. However, as soon as an item is on display in our shops, it will be marked "Showroom" and you will be able to view it in a shop.