I generally use a pick but practice finger style. I've seen and heard of very good bassists (one of which is Geddy Lee) that generally use one finger when playing. For me the timing is shaky when using 2 or more fingers especially on slower tempos. If I do something like a fast gallop, I think you would pretty much need 2 fingers (I lead with the middle finger) which is probably different than most. Paul McCartney uses his thumb for crying out loud, and so do I when learning songs, and then move to a pick. The point is, for me, using a pick results in a much better tempo than using 2 fingers probably because I came from guitar but using just the 1 finger gimp mode might be an alternative to getting a desired sound and result in better tempo. Are there any unforeseen problems using 1 finger?