I hit up the loot cave last night for maybe half an hour or so. Boring as hell, but it's a good spot to farm. Also ran into some even thing where like a billion mobs spawn from the room next to where you're shooting the loot cave from. That was pretty insane. So, in 1/2 hour to an 1 hr, I got around 7 blues and a ton of greens that I salvaged for parts. I'm sure the longer you do it, the higher the chance for a legendary.
I also figured out that a legendary engram, could just be 2 strange coins. So, I didn't do anything wrong when I brought he leg engram over to the decryptor guy and he gave me 2 strange coins.. lol