The hardware sprites of the Amiga were very very weak... but the blitter hardware makes the work, moving "very big amounts of graphical data" fast and without (not 100% true) motorola 68000
So mostly all sprites in Amiga are not REAL sprites, are half-half ("bobs"="blitter objects")
They were rude to mask and background restore (automated in real hardware in sprites)
And the copper list allow to make on-screen-changes (color rainbows, change of resolution, distort effects -waves- and ANYTHING you can manage with hardware registers)
Copper list are hard because you can't make real code,only write a register, wait for raster scan... very very limited (you "compile" the list for the frame and activate it when raster reaches bottom of screen)

EDIT: Uuuuffffffffffffffff... sorry my awful english, I can't do it better!