Primordial had been one of the more interesting Metal bands active in recent years. Like ROOT, they have found their own sound, rather than copying their idols (current doom metal scene), re-recording the same thing over and over (current power metal scene) or wandering away from their metal roots (current black metal scene).
'Gathering Wilderness' should appeal to fans of the band's breakthrough 'Spirit the Earth Aflame' album. You have the same layered songs, with the guitars weaving a melodic but somewhat mournful backdrop for the music (those wanting power chords or riffmania had best pass), the same mournful yet defiant tone to the songs and the lyrics, and the same 'wailing' clean vocals. All good stuff.
The biggest change from StEA is the harsh vocals. Gone are the sick, spiteful rasps that gave that album such a venomous, hateful undertone (really accentuated the angry undercurent). The harsh vocals this time around are, well, different. More understandable, but IMO not as effective at conveying those dark emotions. They'll take some getting used to, and they are prominent in the opening track ('Golden Spiral') so they catch you a bit offguard at first. (this change in vocal delivery may have occurred on 'Storm Before Calm', but I haven't heard that album yet).
In short, GW should please fans of StEA, but don't expect it to top the grandeur of that album
EPILOGUE- adding this 6 months later to note that the album has not held up very well over time. It suffers a serious lack of hooks in the riff department, which allows the songs to just run on and bleed together rather badly. Still not a bad album, but i'd clip one of those stars off for failing to withstand the test of time.