I got the steam version for free when I sent steam a photograph of my Civ IV complete CD set with its unique serial-key visible.No I'm old school with the Original CD sets. Toffer may be the only Modder that uses the steam version currently on the team. The rest of us are long long time Civ players. I still have all my CD sets going back to Civ II.
I also own a lot of old PC games on CD, like Civ III, Civ 1, call to power, age of empires 1, alpha centauri, diablo 1 & 2, might and magic VII, fallout 1 and 2, settlers 2 gold, among others. Ah those were the days.
Once I even had loads of Amiga floppy disc games like "knights and merchants", mortal combat 1, lemmings, but they are gone now.... (sad).