As someone who's been partying with the long maul recently, I think it's fine.
In a support role -which is what it was designed for- the long maul is fantastic. When running with a clan mate, it's easy for me to go 25-2 on a map causing rage all around. I think adding any more weight or damage to the thing would make it ridiculously OP.
For the great maul, it's balanced with it's stupid short range. It's easy as hell to kill the average maul user unless they are a chambering fiend like Palatro.
Poll