The premise sounded absolutely great, reading the synopsis immediately had me sold. Have for a long time gotten a lot out of 'Criminal Minds', though will admit that it has been hit and miss for a long time. The largely positive reactions from fans also furthered my interest. Have been mixed on JJ for a while personally, loved her Seasons 1-6 but the tougher personality felt like the writers were trying too hard to make her more interesting, which wasn't needed, so there was intrigue and worry as to how an episode heavily centered around her would fare.
Luckily "The Tall Man" has a huge amount to recommend. Also nearly forgot to mention that that it was directed by Matthew Gray Gubler grabbed me, being someone that loved the likes of "Mosley Lane" and "Mr Scratch" and someone that knows Gubler does creepy extremely well. "The Tall Man" is among the best JJ-centric episodes, certainly the best in a long time in my view, easily one of the best of Season 14 and the best episode since the Season 14 opener "300".
Did think that a few of the connections in regard to JJ's past were a little reliant on coincidence and more could have been done with everything with the necklace.
On the other hand, "The Tall Man" is a well made episode visually with a lot of atmosphere in the photography for the creepier scenes. The music didn't feel overused, neither did it come over as too loud even in build ups. It is one of the season's better written episodes, very thought-provoking and with tauter tension and emotion than most Season 14 episodes. The story is really fascinating, one of not many episodes of Season 14 to not have a run out of ideas feel. It is genuinely creepy, Gubler was always great at creepy atmosphere, but in a restrained yet unsettling way and not in a gratuitously gruesome way like "Rule 34". It is not a simple case, but it is not an over-complex one and doesn't have implausible plot twists or dullness.
Absolutely loved the character development for JJ, which is both illuminating and heart-wrenching. The episode doesn't try too hard with her, having both the sympathetic element of her character of the earlier seasons and the tough one of the latter seasons (except not heavy-handedly this time). It was difficult to not empathise with her or root for her closure, all done without being too soapy. Although some did/may find the identity of the unsub not the most surprising on the block (though it is not as prematurely obvious as in "Innocence"), that was easy to overlook for me as they are not just creepy they are also pretty sick to put it lightly. Did like their backstory without focusing on it too much.
Did think too that the team's closeness, JJ and Rossi have some lovely exchanges together, and ability to work coherently was more than obvious throughout. They are far from underused or useless and their teamwork, which is plentiful and interesting, doesn't come at the expense of JJ. The acting is very good, with immensely affecting AJ Cook being on the same level of tour de force as Gubler in "300".
Summing up, great episode and one of the best episodes of Season 14 easily. 9/10