Back in the day I was strictly an MD guy, which is basically why I burst fire. I treat it like an md. Also, I dissagree that las kills dretches faster. Rifle fires faster and only takes 5 bullets to kill a dretch. I say its about even.
Honestly, I don't play Humans a lot on 1.1 so I could be wrong, but I thought one laze blast killed dretches.
Sometimes I'll get lucky and the human's MG burst will only clip my Dretch, leaving it with like 5-10hp and the chance at another head-bite (because not everyone is good enough to use an MG as an MD

). That was basically what I meant by "faster". But if Laz needs more than one pop to kill a Dretch, then you're right. It is about even.
In fact, I think I'll go consult the manual real quick and find out...
AND LATER
I couldn't find the damage for weapons listed in the manual
I used "Search" to check the forum but still couldn't weed it out. Did I just not look hard enough?
CONCLUSION:
In the end, I think my point comes down to this:
If your a noob human, Laz Gun is an easy way to kill Dretches and assist when rushing because it doesn't require reloading and it's an extremely accurate ranged weapon.
But if you're a pro like Bauer, the Laz Gun is simply a waste of money.