LG's webOS platform has a couple of new features this year, with the most user-facing change being a new content row called 'AI Preview'. We are still waiting for Apple to roll out AirPlay 2 and HomeKit to LG TV. These features are expected soon but did not arrive in time for our review.
In terms of picture quality, SM90 disappoints. The way it processes video in 8-bit SDR - all non-HDR video - is subpar and especially low-bitrate content from streaming services or channels suffer as a result, with green tint and heavy posterization in shadow details. These issues are not present with HDR content but the TV's limitations in zone dimming (48 zones only), contrast, and black levels, affect HDR picture quality, leading to visible halos (blooming) and limited dynamic range. These limitations also affect SDR picture quality but are more prominent in HDR.
As the only TV maker so far, LG has equipped many of its 4K TVs, including SM90, with HDMI 2.1 ports and features - a plus in our book. Next-gen game consoles that are expected to be available next year will embrace several of the HDMI 2.1 features and LG TVs should be ready. The company has also managed to reduce input lag on SM90 to one of the lowest levels we have measured on a TV to date.