I learned to play a guitar with a pick, so when I took up bass it was the natural move to carry on with one. I practise using my fingers for the whole 'choose what's right for the song' thing but am still unable to play with the same control, subtlety and speed that I can with a pick, so for gigs I exclusively play with a pick. Maybe when I can play to the same standard with my fingers I will be able to choose which style but, tbh, I don't feel that playing with a pick restricts me. I think the most important thing is to play in a way that is better for you - if you have a decent touch with one style and not another I don't see any reason to 'do yourself down' by not playing to your strengths. 99.99% of the punters aren't going to notice - probably only bass players!