Your example isn’t very realistic as you wouldn’t normally be connecting to a “jumping event” using .Jumping and then using :GetPropertyChangedSignal("Jump") in the same script.
I’ve decided to run them in separate scripts to give a more realistic example and .Jumping is actually faster based on the data.
Hopefully this answers your question, as I believe .Jumping is a better option, plus it’s the recommended option on the wiki and I personally will trust the wiki.
Edit: I did edit the data as I was providing an inaccurate example myself as I was using server scripts rather than local scripts, the data above is now accurate though. I’ve also decided to provide my .rbxl below: JumpingExample.rbxl (15.0 KB)