I like the e-laser too. One of my troopers exclusively carries that along with a flamer in the backpack (don't know how I settled for that combo). The e-laser is extremely useful for stunning civvies, either to prevent their deaths (particularly to eliminate them as a friendly-fire liability when in the line of fire) or unblock a doorway. I love stunning three civilians in the same turn (haven't been able to reach four yet...hmm, does this make me evil?). One weird bug is that stunned civilians seem to block shots as a regular standing civvie would, but the "targeting fire line" when choosing an alien to shoot does not turn red to indicate a blocked shot, and the stunned civvie is never killed by any shots it ends up blocking. Same thing happens with stunned aliens.
I've never found D-F cartridge supply to be a problem, because after a month or so following your first workshop-produced one, you can buy it instead. Yes it has a limited supply, but unless you are using a lot of heavy lasers and/or regularly get involved in protracted long-range firefights, it should be more than enough. The only ammunition that I need to produce on-base is PB grenades (and regular plasma hand grenades, as the aliens don't seem to like those anymore).