It doesn't copy whether that permanent is tapped or untapped, whether that permanent has any counters on it or any Auras and/or Equipment attached to it, and it doesn't copy any non-copy effects that have changed that permanent's power, toughness, types, color, abilities, or so on
Flexibility is also useful: Sweepers are not a great replacement for spot removal
Elder of Laurels will let me pump up one of my creatures so that I get to pop a +1/+1 counter on them when they attack
Honorable Mention #1: Skyship Weatherlight It's impossible to talk about the original Weatherlight crew cards without talking about the eponymous ship itself
Which one should I leave out
Gilgamesh offsets all of the downsides to playing equipment, and can create tons of value