This is the spiritual successor of the Nokia N900, and it isn't a very good keyboard (but a better layout than N900). Its pretty much a rebrand of the same device with the same name from 2019 without the 'X'. Difference is it has better OS support (thanks to XDA, I guess), different SOC (recent SD600 series instead of SD835), and a different colour (blue instead of grey).
If you want a very good hardware keyboard use whatever BT or USB (such as HHKB) or try one of the Planet devices (Gemini/Cosmo/Astro). I own a Cosmo, the keyboard is superb. They all have the very same keyboard. Right now, I'd opt for an Astro instead of Cosmo. Also slider instead of candybar + horizontal flip, and a more recent SOC (D800), with a proven track record of keyboard.