Many people compare Maul to Gunnar, but for me personally I like Maul soooooo much more than Gunnar.
I think it comes down to that even though both are domineering, Maul still gives you some space. If you don't seek him out, or if you reject him, he will just say cool and back off. Gunnar on the other hand has some scenes where he will try to humiliate you even when you make it clear you're not into it. That's just uncomfortable for me.
It's a fine line but I think it's an important one in D/s writing.