on paper 36v is a little more powerful, 37vx19A=703W 48.1vx14A=673W I would go for a 11s battery so that's an even bigger difference, 11S=773w vs 14S=725w. max voltage 11S46.2v=877W 14S 58.2v=815W. I calculated 58.2 because 48v firmware has a max voltage of 58.4v.
another advantage is smaller...