Josef Rheinberger, well known for choral and organ music, may be somewhat a bridge between Bruckner and Brahms.
The Symphony #2 in F Major, the “Florentine”, is a massive work (53 minutes), and seems to be fairly youthful. The first movement and finale are a bit Mendelssohn-like – and let us remember that F Major is a key that seems to usually have a more pastoral personality (like the Beethoven #6, or even the Brahms Third).
But the 18-minute Adagio, in D Minor, is indeed monumental, anticipating Bruckner (especially the Fifth Symphony Adagio in the same key). There is a second subject that sounds like a familiar church hymn tune, that raises to ecstatic climaxes twice. The harmonic palette is closer to Brahms than Bruckner (Rheinberger hadn’t learned the value of unresolved dissonances yet), but Brahms’s slow movements tended to be simpler and more Andante-like.
The Third Movement is a Minuetto,in A Major, rather than a scherzo, but is quite extensive – but again a little bit Brahmsian, and well worked out.
The Finale has a race to a jubilant finish that rather reminds me of Berwald, and perhaps Stanford (the Fourth Symphony, also in F).
Note the art work in the video, a vista on another planet, with a spindle city enclosed in a dome to provide a breathable atmosphere.
I have the OW CD with the Northwest German Radio Orchestra with Alun Frances.