One of the major changes that Google announced was that Pie was optimised for lower-specced devices.
Seeing videos online though, it appears that it is smoother and zippier than Oreo, even on low end Amlogic hardware.
Thinking of getting either a Vodafone TV or Mi Box S for Android Pie. As my Sony X8000D is now three years old and stuck on Oreo.
Both the Vodafone TV and the Mi Box S have virtually the Exact same (HDR capable) chipsets in them.
One with a S905D the other with a S905X, both from the 2015 era. Both have an ARM Mali-450 GPU.
The Vodafone TV has better connectivity, but if you upgrade to Android Pie 9.0 on it you will lose NTFS Hard Drive support until Firmware gets fixed.
Android 8.0 Oreo came with a very noticeably performance increase on cheap Android TV devices.
Android 9.0 Pie had further tweaking so it could run on dirt cheap devices with as little as 1GB RAM and 1.2GHz CPU’s.