I think it's six decibels from one, half a dozen decibels from the other.  
I have several roosters, some full-sized, some compact models.  They all sound about the same in terms of loudness, but the pitch varies depending on the individual.  You also have to figure that what bantam roos lack in size, they more than make up in attitude.  So a banty might not crow as deep or as loud, but he might feel the need to crow more often.
The worst-sounding crow I ever heard was from a Sebright we had.  He sounded like a screechy wind-up toy, and he made noise all throughout the day.  He also was an ankle-jabber, making it perilous to cross the yard in one piece.  It was such a relief to finally get rid of him!
The best-sounding crow I ever heard came from a huge White Jersey Giant we used to have.  Buck had a deep, rich baritone crow, he should have recorded albums with that voice.  
You're just going to have to make peace with that neighbor, resign him to hearing crowing from your yard.  Bribe him well with fresh eggs, and buy him some ear plugs.