I've done this LASO twice now... the first time took 2 hours & 15 minutes and I only accounted for 5 of the 82 deaths... LASO 1
The Second run was much faster at a mere 56 minutes and 11 Deaths for the party (I was 3 of them)... LASO 2
I can upload the videos if anyone wants to see them...
They are rather pointless overall... but you may find some useful tips and hints mixed in to assist you in doing this challenge.
The biggest tips I can give you though... are to take your time, using cover, to snipe with the DMR (sometimes going as slow as only one shot per second)... and DON'T be anywhere near the door to Dr. Halsey's Lab if you can help it... hijack a Banshee or a Wraith and kill from LONG range (it takes a bit of time... but well worth the time spent if you aren't restarting every couple of minutes).
Anyone else have useful tips and hints for this challenge? I may do it a couple more times this week to see if I can get through without dying at all.