This may seem simple at first but when not when sailing this up to large models ect but also scripts are smaller and should replicate to the client faster when compared to large models?
Scenario 1 creating a projectile using clone :-
local bullet = -- stored pre made bullet
local newBullet = bullet:Clone()
-- set other params ect
-- shoot bullet
Scenario 2 creating a new projectile each time:-
local bullet = Instance.new("Part")
-- set other params ect
-- shoot bullet
I hope this explains my question but just in case another example could be, creating a model in a localscript or cloning one from the replicatedstorage.
Pls comment if you need any more info.

2 comments
scratch that, nanoseconds :D
No I think it's probably closer to microseconds sadly, unless your CPU is fast enough.