Substance wins hands down for me. There are a few reasons. Most importantly it was what got me into New Order in the first place. My mate had True Faith 12" and i taped it. then he got substance vinyl and i taped that too. i hated the first 3 tracks for a couple of years (sounded too samey).
about 1991 i bought the CD version and realised the beauty of the first 3 tracks. i think the 12 songs on the A side are the strongest by any band ever (yes even U2!).
i still think today that that album has some of the most beautiful, lush music ever made (period).
the B side is pretty tasty too. not so much the instrumental versions but for Lonesome Tonight, 1963, Shame of the nation, kiss of death and procession and mesh.
i think this is my favourite album of all time. Technique my fave studio album too.