In FO3 I saw no reason to drop my 10 MM for the Laser Pistol that was in the Mart, couple that with the rarity of the ammo, that kind of put the brakes on pursuing energy weapons for most of my characters. Later on in the game I would use a few energy weapons but by then my skill was so low relative to the other weapons, that I just never saw the need to use them.
I think what there should be is low level energy weapons at the beginning of the game if you choose to use them, but only the powerful fun ones later on in the game. The early weapons would offer no real advantages in damage/accuracy/range over the pedestrian chemical weapons that you can get early on. Perhaps tie this to the condition of the weapon as a low level character would not be expected to have a high repair skill to boost the performance through repairs.
E-weap ammo really isn't rare, it's just... expensive. Loot the Robco factory for all its worth to get a healthy stock of ammo early on. Only mole rats and roaches at that point.
Beyond that, the only things that the 10mm pistol has up on the laser pistol is ease of repair and a less sticky trigger (lessened with proper upkeep). Durability is superior, accuracy is superior, damage is superior, mag size is superior.
The gun I have problems keeping fed is the Assault Rifles. I'm swimming in E-cells and MF cells.