At the early stages of the game I just used quicksave and quickload to see if people were worth mindreading - as well as the stat/skill bonuses, there are certain quests that can only be solved with mindreading, so it's worth doing if you have the time.
Later on you'll be able to train mindreading up to level 15, at which point it won't cost any XP, so the problem is solved. I didn't start mindreading everyone until I had maxed out mindreading, but I've found so many extra still points that I wander if I should have done more mindeading earlier.
Definitely mindread everyone in the "Hall of Echoes" - almost everyone gives you a skill point.
