Are you serious?
A lightning bolt is nowhere near the same as Raikiri. Raikiri just activates the muscles, the same way as Ay does and makes the person faster.
However, the energy used in body or torso as Ay does, is not the same in Raikiri. Raikiri concentrates the energy on finger tips, leaving minimum of energy behind in the Chakura canals.
The lightning bolt has almost no mass, so it travels free and as fast it should. However, carrying a person with it is more difficult by logic.
It doesn't matter how strong, lightning bolt is always fast. It's like saying is Chakura made water dryer than normal.