Another datapoint....on my recent flight there were two ladies transferring JNB-LOS-IAH and I've never seen two travelers who looked so like they'd been through hell and back.
They were ranting on and on at the purser about what a hell it had been, etc etc, and how dare United give them such a routing. "Sure we'd heard about Nigeria but thought it was exaggerated." They learned otherwise.
That said, I had no troubles at LOS at all, but it's definitely not for the inexperienced traveler.