The Roku Ultra 2020(Model # 4800, released October 2020) has 4GB of Channel Storage and 2GB of RAM. the only downside that I was worried about was not having a MicroSD slot but the sheer amount of channel storage has alleviated that worry
ARM Cortex-A55, Quad Core, 4K UHD GPU: ARM Mali-G31 x-core
spec wise and only for games it is not as fast as google chrome and fire tv stick 4k max.
Having said this I owe 2 Roku devices. One Roku express 4k and a Roku ultra 2020 (purchased a week ago). Where Roku excels is Airplay 2 support. Love it. For Roku ultra it is additionally wired Lan support and bluetooth headphone from remote control.
I also owe a Google TV which is also good in games from playstore and stadia. Comes with better cpu specs: