These strings have the classic 50s/early 60s sound. More specifically they have the sound of American vintage soul music. They do start out as quite metallic and bright sounding though, and NOT in a nice way. They take quite a while to break in but once they've settled they sound fat and thumpy and last for decades.
They are high tension, VERY stiff and not suitable for anything that requires a bright tone or lots of sustain.
Highly recommended if you're looking for a fat, warm, thumpy Motown/Stax-style sound.
Stay away if you want a modern,crisp sound with lots of sustain. They're classics but not very good allrounders.