Custom "Tav" only. Since I play only male characters, my choices would be limited to Gale, Wyll and Astarion and neither of them is appealing to me for one reason or another (mostly their classes). Yes, I could technically respec their class to a class I actually enjoy to play, but playing Gale or Wyll as a fighter, paladin, ranger, monk or barbarian would feel strange as far as their origin is concerned.
Also, I prefer to play my own characters in RPGs. This does, in fact, extend to companions as well... if we could create multiple characters without having to rely on a workaround, I'd do that in heartbeat.