The Legion displays all games smoothly on its matte 15.6-inch display (120 Hz FHD, IPS). The integrated GPU is activated as a standard but can be deactivated with the click of a button. The battery life is very good as well.
https://www.notebookcheck.net/Wish-you-could-turn-Nvidia-Optimus-on-and-off-The-Lenovo-Legion-5-15IMH05H-lets-you-do-just-that.480917.0.html
I wish all Optimus-equipped laptops had this feature. I mostly use my laptop plugged in so I don't even get its only advantage, just the problems.