Have been pondering the obscure category a bit more.
Bloch: not sure it quite ever gets to great.
Szymanowski: probably not helped by the recordings I have being from Gergiev and Rattle but the symphonies aren't a patch on King Roger or the Stabat Mater.
Glazunov: competent but not earth shattering.
Brian: not great other than scale for the Gothic.
Lloyd: enjoyable enough, but not much more.
Alwyn: close, especially in 4 but not quite.
Bax: reaches a high point in the 6th which I would be happy to put up against the recognised greats.
Bliss: the Colour Symphony is brilliant and not played nearly enough.