I personally love Mater. I think he is easily my favorite Cars character. I liked him back since the first teaser with The Incredibles. At first, I wasn’t sure what to think when I heard he would be the protagonist of the sequel, but afterward, I think it kind of makes sense. To have Lightning McQueen be the main character might have been missing some heart. Also, if the first movie was about Lightning learning to live in the slow lane, why not have Mater experience the fast lane and learn to stay himself in Cars 2? It may have been a unique test to Mater in a fun way like the older Pixar films rather than as dramatic as the few films before it. Just my thought though.
He’s okay. I dont love him, I dont hate him. I didnt like him enough to want to see him as a main character, as I thought he worked better as a supporting character. Or maybe I just didnt like seeing Lightning regulated to that role. I’ll admit I didnt really like him much at all at first, but after a few viewings of Cars I got used to him.