I find it funny that the long maul is terrible against anyone with a heavy shield or heavy weapon (great maul), yet the great maul rapes those same things. The long maul weighs 1 less kg than the great maul, and has a longer handle for a harder hit.
With the long maul you can actually maul through shield walled team mates, from safe distance p.e.
The same reach allows you to backpedal in safe range while crushingthrough the enemies.
This is an heavy advantage, which was obviously taken into account by the item balance team.
I've given already some tips of how to fight against a mauler (at least a decent one).
If you wanna make comparisons with polestagger, do this mind exercise:
a) realize that maulers are with luck 3 or 4 at the same time;
b) also realize that polearm users make most of the time almost 40% of a server (including cav users, also staggers);
c) obvious conclusion.
It's simple facts and mathematics. A polearm user hits you once, if it staggers, good luck. Either he'll stunlock you to death, or the rest 40% will, or even the other 60% will take advantage of the stun (most likely).
A mauler hits you with overhead? You have at least 50% chance roughly of being able to counter first by using the brains and smart footwork + faster swing.
A mauler by itself is completely useless in most scenarios; a mauler that knows HOW to act, WHERE to act, and how to apply TEAMPLAY and TACTICS, might be your worst nightmare.
When that happens, this happens (nords teamplaying with decent tactics):
http://i.imgur.com/OCXbB.jpg Also the most formidable mauler isn't the one with tincan suits and pure str builds. Run from those with actuall WPF and medium/low gear. Run... really run!