I think he's a great character and pretty underrated.
People tend to call him a jerk because he shows a more serious demeanor for the most time and he can be rather blunt at times. However, I think that's an unfair accusation: yes, Mace is more stern and more reserved than, for example, Obi-Wan. But that doesn't make him automatically a bad person. He's still shown to care for others, for his fellow Jedi, for beings in need of help. Mace isn't just a random Jedi, after all, he has immense responsibility weighing on him, as a general fighting in a war, as the leader of the High Council, not to mention that he has to fight his own demons as well. There were some specific parts in the shows where I thought he wasn't particularly sensitive or tactful (admittedly not one of his strengths) but I never really thought he was a jerk. He's certainly far from being perfect but that makes him just much more human and doesn't automatically make him a bad person, either.
I think he's overall a pretty strong, admirable, and also likeable guy. A Jedi doing his best in a period of turmoil and darkness
