At least some of his message is appealing to people. Conservatives either like him a lot or dislike him and think he isn't a serious candidate.
He's a bit of a dichotomy. He has many conservative views and has supported some conservatives, but has also given money to radical Democrats such as Harry Reid and Hillary Clinton. He is very good in interviews, heaps glowing compliments with the interviewer, and appears very likable. He also can be extremely thin skinned when someone criticizes him. He holds grudges and involves himself with petty public slamfests with people such as Rosie O'Donnell and NRO's Jonah Goldberg. His large ego makes him prone to silly political mistakes, but it also helps him to be bold with his message and ideas. His pluses are that he has some bold ideas and is an interesting person who grabs the attention of people. He'll make a very interesting candidate. He also has plenty of money to compete. His minuses are that his braggadocios trait will turn some people off.(maybe a lot) He will probably say some things that will be lambasted in the media. He'll have to endure the unrelenting caricaturization by those in the media and political pundits.
IMO, he's is a person that I mostly like, but there are a few characteristics about him that I dislike as well.
I read somewhere that if it came down to Jeb Bush or Donald Trump to vote for, he would pick the latter. I can't say that I would disagree with him.