Be good exchange for trading maybe yes, but be the best is something that can't be decided by someone. But maybe if want to review and give good opinion, i think it is ok. But for me any exchange is good because we can use all of it.
Users experienced will play the big role here, everybody have their own qualifications in terms of being the best, as long as they are comfortable and satisfied with how an exchange caters their needs it can be accepted as best but claiming to be the best needs to compete well with many exchange out there which already been tag as the best from this market.