In Paper, vanished players are better hidden. Arrows, fishing hooks, and other projectiles can fly through vanished players, as if they aren't even there. Players can place blocks even if someone is invisible standing directly in front of them.
Undead horses can be leashed, as though they are just normal horses, if you so want them to be
Squid Spawn Heights
The spawning height of squid entities can be altered via our config file
Blocking Damage Modifier
The damage modifier a player gets for blocking (right clicking with a sword) is configurable
Cacti and Reeds
Cactus and Reed growth height can be altered in our config file
Baby Zombie Movement
The speed at which baby zombies move can be altered
Fishing time ranges
The amount of time it takes for a fish to be caught can be altered
Nerfed Mob Jump
Spawner mobs nerfed via the spigot.yml config setting, are allowed to jump in Paper, to reduce breakage of vanilla gameplay mechanics, like spawner traps
Configurable Despawn Ranges
The vanilla ranges that control when entities are despawned can be altered.
Falling Block Height Nerf
Falling blocks can optionally be removed from the world when they reach a certain height, nerfing long range cannons
In Paper, chests and enderchests do not tick, improving server performance
The server tick loop has been further altered to improve performance
Nether Void Damage
The server can optionally apply void damage to those that get above the nether's bedrock roof
Multiple internal changes to help redstone act more like it did on a vanilla server
Async Light Updates
The server can optionally handle all lighting updates asynchronously, offloading the task from the main game loop and improving performance
Disable Player Crits
Critical hit attacks by players can be disabled to alter gameplay
The end game credits that appear when leaving The End dimension can be disabled
Flying TNT Entities
TNT, FallingBlock, and Enderpearls can be configured to either load chunks as they fly, or be removed from the world when they reach an unloaded chunk. Preventing players from using long distance cannons to shoot through terrain
Buckets can be stacked by type, enabled for milk, water, or lava individually.
World Generation Settings
Numerous world generator settings can be controlled from within Paper
1.7 TNT Behavior
TNT can be reverted to behave similar to the way it did in Minecraft 1.7, bringing cannons back to life
Timings Version 2
Paper implements Timings Version 2, the latest revision of timings. Offering increased detail and performance to server timings
Improved Chunk Saving
Will retry instead of giving up after a failure, and also fixes race conditions that could result in chunk rollbacks.
Configurable Non Player Arrow despawn
Make arrows fired by skeletons despawn quicker since players can not even pick those up.
Use $sender in commands.yml
You may use $sender to represent the sender of the command in your commands.yml aliases.
... and many many more! (this list is hard to keep up-to-date)