I'm generally a big fan of Priest's work, but having finished his three volumes of Captain America & The Falcon I can say that it's not one of my favorites.
First, the "Disassembled" interlude totally mucked up the whole middle of the arc. Worse, it gives Cap weird hallucinations and it totally changes Falc's characters. Yet despite the major influence on this arc, we never get a solid explanation. (Falc's reversal is also somewhat annoying because it's so out-of-character.)
Second, the whole story is so dark and gritty — both the drug connection and Sam's darkening character — that it feels out-of-character for a Captain America storyline.
Third, the storyline just seems to go on-and-on. 14 issues later, it feels like it went on for way too long.
There's a nice MODOK interlude in the middle of this, but then it's back to the same 'ole issues of the Anti-Cap and bad Falc.
Even though I like some of the storytelling, as a whole I'm just thankful this story is over. However even there I really didn't love the non-ending that's been largely ignored by later books. (I couldn't even tell if Falc was alive or dead when I first read this, because the non-ending is so murky.)