That question is a bit like a opinion, for people who know how to play with a particular pokemon will say that is good, for people who don't know or don't like using it will say that is bad. In the end there is no right or wrong for this question. For me in particular, is very good in battle, other people will have different opinions based on their taste and gameplay. Sadly, they don't know how to be impartial.
(But, being impartial and don't giving my opinion, saying just what really is, he has good stats, a wide movepool and good moves to make good use of his better stats, so in terms of overal, he is very good)