Actually, I think in the example, the #s should not denote the threading level.
Instead of:
1 (starting post)
--2
---3
----4
----4
----4
---3
---3
--2
---3
---3
It should be more like:
1 (starting post)
--1.1
---1.1.1
----1.1.1.1
----1.1.1.2
----1.1.1.3
---1.1.2
---1.1.3
--1.2
---1.2.1
---1.2.2
So in the threaded/flat model, if you were viewing message 1.1, you would only see (optional # replies):
1.1
-1.1.1 (3 replies)
-1.1.2
-1.1.3
You would no see 1.2.1, etc.
Yeah, I bet this is as clear as mud!
Kiliman