Is it like Sicario where it leaves you devestated?

The particular scene I am talking about, yes.

Personally, Sicario did not leave me devastated; I assume that you are referring to the Benicio Del Toro character's massacre of the drug kingpin, his wife, and his children, and that boy having lost his drug-dealing father, but correct me if I am wrong. What happens in Sicario is certainly very suspenseful and brutal, so I appreciate where you are coming from, but it did not devastate me because I felt that the plot ultimately amounted to a typical Hollywood revenge potboiler, even as the director (Dennis Villeneuve) strained to impose a greater social meaning that the plot failed to justify. Thus, despite some excellent aspects (stunning aerial shots, great use of atmospheric Southwestern/borderlands locations, effective score, pulse-pounding action scenes that are well-staged and sharply edited), I felt that Sicario merely amounted to a "decent" film. The milieu is fascinating and the technical aspects are strong, but I felt that the narrative proved banal—not bad, but a bit too hackneyed to leave me devastated. That said, again, I appreciate learning of how someone else responded to it.

As for Hell or High Water, having just seen it tonight, I feel that it is a good film with a great ending—a classic ending, in terms of a brilliant final scene with exceptional dialogue, acting, timing, and gestures. But that brilliant final scene is a coda—not a blow-you-out-of-the-water spectacle or anything overtly dramatic. To fully appreciate it, one probably needs an appreciate of subtlety and perhaps a feel for the genre (or quasi-genre, or sub-genre). The ending is reminiscent of a classic Western, and Hell or High Water is something of a modern Western. Although not as great, the coda here is sort of reminiscent of the coda in The Outlaw Josey Wales (Clint Eastwood, 1976) where characters talk to each other through a kind of code—Western code. The meaning and mood here are very different from Josey Wales, but the sense of vernacular and rhetoric and the implicit exploration of masculine ethos, which one also finds at the start of Butch Cassidy and the Sundance Kid (George Roy Hill, 1969), is similar.

Hell or High Water offers a no-frills, dryly ironic approach to its subject matter, as opposed to Sicario's manufactured drama and strained meditations. The film from last year that I would compare Hell or High Water to is the little-seen, low-budget, seriously underrated yet very good Cop Car. The movies are not that similar, but the settings, milieus, and spare, no-fuss approaches are comparable, and both films offer ambiguous and open-ended denouements that force the viewer to think for him or herself.