It's probably not realistic to talk about this album without acknowledging one's obvious bias toward the recording, that is, it's impossible not to know that the songs were assembled long after Cash's death. With that in mind ... there something plastic, overly polished, and fake about some of these songs. Cash's "American Recordings" series are known for their no-frills, rootsy, back-to-basics approach. The first album was little more than one man and his guitar. Subsequent albums gave greater prominence to extra guitars and piano but the overall feel remained very stripped-down and basic.
In short, Cash's voice doesn't sound up to the task throughout the record. His voice (and health) progressively and precipitously worsened over the last ten years of his life, which might have added poignancy to the song and video for "Hurt" but gradually depleted the quality of his recordings in an overall sense. Here, his weak, gravelly voice is coated over clean, chiming guitar picking, which practically advertises the fact that he wasn't in the same room (or, uh, planet) when the music was being recorded. A voice that weak doesn't feel credible leading such a polished-sounding band, and the juxtaposition of the two is very out-of-step with most of Cash's back catalogue. "Back on the Chain Gang" is a more classic sound for Cash, as his voice recedes into the mix, in short, it sounds like raw and unprocessed Cash. "On the 309" is a great rustic country song in the vein of "Tennessee Stud" (AR1) or "Country Trash" (AR3) but it's badly in need of a singer that doesn't sound exhausted on every verse. Ditto "Rose of My Heart", which is a pretty tune nearly ruined by Cash running out of breath at the end of nearly every line.
On "Four Strong Winds", his voice protrudes over and above the recording. It sticks out too much, possibly because they protooled him up to make a low quality recording (or vocal performance) sound better. It just doesn't sound like him. Similarly, I have to mention "If You Could Read My Mind", partly because I think it's one of the most beautiful songs ever written, partly because Cash's AR cover songs are probably the most well known recordings in the AR series (Hurt, One). Cash prided himself on learning these songs until they became his own -- indistinguishable from a Cash original if you had never heard the source recording. Again, the voice is too high in the mix, coming across like overly digitalized Cash. Over intricately picked acoustic guitar (very Lightfoot, but very un-Cash), the song proceeds at a slow, crawling pace, as if Cash is too weak and out of breath to keep up and needs the song slowed down for him.
Still, there is a fragile beauty in the weakness and vulnerability of Cash's voice, making "American Recordings V" a pleasant (but not the least bit arresting) listen. But unfortunately, it really and truly sounds like the end.