I reread this thread and went and checked some Seasick Steve videos on YouTube. There's some great music on You Tube if you make the effort to find it. There are also several Seasick Steve videos.

Setting aside the question of "authenticity" and just listening to the music on its merits... well, if I want raw back to basics guitar and simple percussion, the White Stripes will do it better. If I want simplicity, driving rhythm and excitement, then Muddy Waters, or Bo Diddley will do it better. If I want a rabble rousing entertainer, Chuck Berry. If I want quality modern electric blues (not a fair comparison) then there are people like Gary Moore. Seasick Steve just rang none of my bells at all. He comes across to me as a caricature of a bluesman, certainly not an archetype.

Or, another comparison, perhaps: Sid Vicious playing Eddie Cochran songs. Frantic, exciting: it grabs you by the throat in a way that Eddie Cochran doesn't... but after about 2 tracks you realise that although the king may not actually be stark b*ll*ck naked, he is seriously underdressed for the occasion.