[wrxtasy]

If you are talking about a Heavy Skin that has a bucket load of Textures and Artwork, then 2GB (or even 1GB) AMLogic S905(x) boxes are fine when running the lean and mean OSMC or LibreELEC Kodi Krypton.

RAM quantity has nothing to do with it when we are talking about streaming video. Even 1GB is plenty.

DDR RAM Speed however will have an effect on Media Player Box speed when combined with a fast internal bus to move around all the data.

All those textures and artwork rely on three things to display them at at decent, usable speed:
a) DDR RAM speed.
b) Fast Flash storage - SSD is faster than eMMC and that is faster than a microSDHC card.
c) A decent GPU to draw it all onscreen

So in order of the best for really Heavy Skins:
1) Modern Intel Machines with SSD storage & decent GPU's. LibreELEC preferred.
2) nVIDIA Shield
3) Other eMMC Flash Storage based Hardware like AMLogic S905 boxes running OSMC or LibreELEC

In general the Android OS will add some system resource robbing overheads due to the number of Apps that are minimised at any one time, which then requires low level memory management and garbage collection routines to keep everything running smoothly. There can be some system slowdowns (not video playback slowdowns) on 1GB Android devices for example when these routines are running in the background, killing Apps when RAM runs low.

Each Android OS release gets a speed bump as the OS itself gets further optimised. So Nougat > Marshmallow > Lollipop

You usually don't get that with OSMC or LibreELEC devices, because the sole focus is on running Kodi as efficiently and quickly as possible.
Last time I tried the Aeon MQ7 Skin on the S905 LE ODROID C2 with eMMC for example, there were not any annoying slowdowns.

Combine all that with a Wireless remote control, and you get quick Graphic User interface responses, without annoying missed button presses or slowdowns.