Compact and UPS-friendly 1x1 loaders. Works with train cargo wagons, circuits, filters, and modded belts from Bob's, Krastorio, FactorioExtended Plus, Space Exploration, and Ultimate Belts.
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Is there any different functionality between the two or just aesthetics?
Quite different. Miniloaders can be circuit connected, and they work with cargo wagons and other vehicles at full UPS.
I'll stick with miniloaders then. Not sure why anyone would use the krastorio ones outside of aesthetics.