My experiences at LAD are nowhere as dismal or morose or scary as others' experiences seem to be. I've never had to bribe anyone for anything, etc. The airport is a pithole no matter how one looks at it, but it's doable. If one has access to one of the lounges on outbounds, more power to you, and I would consider taking my own life if I didn't have lounge access. The positive bag ID on checked luggage on outbounds is equally annoying. However, as with much of Africa, if you go with the mindset that you'll simply go with the flow, do what you're told within reason (like wait in a coulple of useless lines, etc.), there should not be any problems - or have not been for me, or a close relative who veritably commutes there (for Big Oil) and spends way too much time in Luanda.
Inbound immy is indeed a bear, never found a way around that one.
For the outbound, I've never had to wait for more than 30 minutes to get to checkin (flights are always/only on Air Namibia C and TAAG F), and never more than 20 minutes to pass immy - and I'm not nearly as important as others who have been travelling on Serious Government Business as Guests of the Nation, etc. I'm just a businessman with just a plain passport. To say that the best thing to do in LAD is leave is small-minded. Is it depressing? Sure. But it's survivable, and always is - and sometimes it's even interesting.