I don't dislike him. He has a good attitude, is fairly competent technically, and doesn't hide. That being said, he's a bit timid, and doesn't look to become a player who'll ever dominate games. Lacks the agression/drive or the supreme passing ability to be able to d0 that. Which is fine. He doesn't need to be that player. How I really envision him playing is as the 3rd midfielder rather than as part of the midfield two. He's got good movement and intelligence, two good feet - logic suggests he should be good playing on the tip of a midfield three, and scoring goals. That's the part of his game that I hope Kenny and co. help him work on for I can't see him developing either as an enforcer or a playmaker.
Having said that, at 16 million, all you can really say is that he's been the best of a bad bunch of very expensive signings. >🙁 I'm not even sure why we even bought him when we had in Shelvey, a player of comparable talent, who would have done at least as much as Henderson has done had he have been given the same amount of playing time.
IMO for some reason, Kenny had plans on getting rid of Meireles in the beginning of the summer (for whatever reason) and had identified the need to have a younger long term replacement for him. Henderson may well turn out to be a decent player, but 16 million will always have been a wasteful expenditure when we had Shelvey around, and when midfield players of comparable/superior talent (Cabaye) who went for 1/4th the price to a lesser club in the same transfer window.