Yes, correct polarity matters, but I don't obsess over it. I also have the 390s and some music is better inverted, some is better normal.
Is it label-dependent? Here is a list which I obtained through a previous post.
Normal or "0" polarity: A&M, Acoustic Disc, Atlantic, AudioQuest, Blue Note, Caprice, Chandos, Chesky, Chess, Columbia, Concord, DMP, Elektra, Geffen, GRP, Harmonia Mundi, Hungaraton, Hyperian, JVCXCRD, Klavier, Liberty, Manhattan, MusicMasters, Nonesuch, Novus, Opus 3, Orfeo, Philips, Polydor, Pope Music, Reference, Reprise, Sheffield, Supraphon, Verve, Wilson. ECM also belongs in this list, IMO.
Inverted or "180" polarity: Analogue Productions, ASV, BIS, Capitol, Cypress, Delos, Deutsche Gramophone, Discovery, EMI, Epic, Impulse, L'Oiseau-Lyre, London, MCA, Mercury, Motown, Nimbus, Pangaea, Polar, Private Music, Riverside, Ryko, Shanachie, Sony, Telarc, Teldec, Vanguard, Virgin, Vox, Warner Brothers, WEA. I would presume that English Decca/Argo belong in this list.
From my limited sampling, this is around 80% correct.
The key is to listen relaxed. Enjoy what you think is more natural!