feigao 6xl or 3s of 8xl on 4s

What would be the better option in an e-revo (gorillamaxx conversion):
feigao 6xl with 3s lipo (aprrox. 30.000rpm)?
or feigao 8xl with 4 s lipo (approx. 30.000rpm)?

Both configurations will reach approx. 30.000rpm, so in theory they would be able to reach the same speed.

A 3s lipo configuration would be slightly cheaper and lighter, but on the other hand the 6xl will draw more amps, right?

Can anyone tell me what de advantages/disadvantages are of both configurations?