Keep in mind there are different intensities of withdrawal based on duration of use..... I didn't read all of the posts, but a lot of them seem very extreme.
First of all, depression isn't really that big of an issue if you've got some benzos or just a good mindset to start with. I find that the stronger the withdrawal, the less "sad" you are because you're in more pain. Then again, when w/ding from oxy, I find I do feel a little emptiness in my chest, sort of like that feeling you get when you're really upset or have just gotten dumped, shot down by a girl, etc. But with heroin or fentanyl withdrawal, for example, I've never gotten that tremenduous sad feeling.
The biggest symptom that I never really expected my first several times withdrawing, just because people don't really go into detail about it, is this extreme weakness that goes beyond simpe fatigue. It feels as if you haven't eaten in several days, and it is difficult to do things without getting tremors/shaking a bit- also this involves pain when lifting things or walking up sairs, stuff like that.
I think opiate withdrawal can be compared to not eating for 2 days, combined with an itching crawling feeling under your skin (which turns into straight cramping pain) that you would normally maybe get if you were drinking earlier in the evening and its around 4am, you're trying to sit still at the table, dying to lay down (except it doesn't go away when you lay down).
Sorry if this post wasn't quality, but I'm far from withdrawing from opiates, and closer to nodding out.