Indeed, Terminal C vs. A is a big difference. My worst airport experience has been trying (and failing, twice; on consecutive days) to fly from Tegel Terminal

Indeed, Terminal C vs. A is a big difference. My worst airport experience has been trying (and failing, twice; on consecutive days) to fly from Tegel Terminal C to Helsinki (EasyJet). My best airport experiences have been flying from Tegel Terminal A (Finnair) to Helsinki.