I'm still on my first character, created by in November, at level 46, game time 556 hours. Still haven't gotten down to Nick yet or the Combat Zone, and most of the South, SE, and SW parts of the map are as yet unexplored. I do a lot of settlement construction, and redo a lot of construction as I learn more about it and unlock new things with every issue of Picket Fences. Easily, 200 of those hours have been spent in settlement construction, going back to help defend, and completing the never ending Garvey/Minute Men quests. I also like to complete all side quests, miscellaneous quests, and faction quests (those who I ally with) before completing the game. I've never been one to play much after the endgame, even back in previous Bethesda games that allowed it. Just doesn't feel the same to me.
I also rarely fast travel, wish I could say "never", but some of the timed Minute Men quests I felt I had to because I didn't know how much time I actually had to complete them. This is the first Bethesda game that I have used fast travel, it's been one of my "internal rules" not to fast travel. I'm looking forward to the new survival mode that will not let me fast travel.
My character also has only 2 Endurance & 4 Strength, uses only light armor and sneaks/snipes a lot. With only 2 endurance, I can get one shot killed pretty easily, this keeps me on my toes and keeps the combat interesting. There are also some perks I will not take as I feel they make the game too easy. Aqua Boy is one, I want the challenge of holding my breath under water, or consuming a Mirlurke Cake (I think that's the one), that allows temporary breathing under water. I also don't take the 2nd level sneak perk that prevents you from setting off floor based traps. I want to keep that challenge. There are others, but those 2 came to mind.
More than likely, I will start a new character once the DLC starts to come out.