My first couple of characters are just for fun and to learn the game and when some good mods start coming out I'm sure I'll be playing more seriously, but for now I'm having a blast. And I also have been using FT more than I normally have in the past, mostly to save time as others have mentioned.
I'm sure I just haven't figured out all the safe routes yet, but another reason I've been using FT is that I'm just tired of having to fight my way to every place I want to go in the city ruins. Many times I just want to get from point A to point B and they put so many hostile areas throughout the city ruins and it's so densely packed that you are basically having to fight raiders, muties and gunners almost every corner you go around - sometimes all at the same time. It just gets monotonous when I just want to get my haul back to base, or get from say Diamond City to Goodneighbor in relative peace, lol.