J.E. Sawyer mentioned tweaking explosives. However, I think he intended to tweak blast radius (AOE) not damage. They seem to have sufficient damage for the most part, but need too much precision in placement.
Some explosives are fine, some are really weak. The grenade launcher isn't as powerful as it should be (the machinegun is overpowered, however) (imo) with 3 ranks of demo expert. Same goes for frag grenades, dynamite, and land mines; they aren't powerful enough.
Usually I'm for realism be damned, but in the case of explosives it makes me go "whaaat..." when I see a grenade go off between somebodies legs and it takes off 15% of their hp. It really cripples the skill from being a main-weapon type and puts it into the category of "I pull enemies with this, and hope I cripple a leg, then I use a real weapon".
Furthermore; blast radius is fine. Any more and you'll be in greater danger of hitting NPCs you don't intend to (allies, companions, neutrals etc.).
VATS is all the precision -any- weapon needs. Manually aiming grenades isn't really that difficult either. Not hurting allies that melee on the other hand... is. =P