This is my first play-through and I chose it(I didn't have the stats for Solar Powered and VATS didn't need to be any easier by choosing Grim Reaper's Sprint...which seems to have gotten nerfed in New Vegas...) so I can visit all the major areas(and not-so-major areas) before I continue with the Main Quest.
Ninja is pretty much useless to me as I don't like using the Unarmed/Melee template, so that pretty much left Explorer as the Level 20 perk of choice.
I have not yet started Tranquility Lane. I enjoy finishing all side quests and exploring before continuing with the Main Quests. I did the same thing with Oblivion(I still haven't visited the Cathdral! LOL!).