As a UNIX pro/admin/user for 15 years also, I have to agree here, I've said it before on here, but I think the whole "Nested Folder" thing is more appealing to ex-Windows users than anyone else. That way they can stick their Application folder and pretend like its a "Start" Menu.LOL I can't stop laughing about this one.
As a person that's been using unix for more than 15 years I've used a folder in the dock exactly 0 times. Hardly a "pro" feature of the OS, IMO.
Personally I feel that nested menus need to be abolished all together, especially ones that have more than 1 level of nesting. Its such an inelegant way to navigate around something.
EDIT: I should also add that I find Stacks useful for one reason only - giving me easy access to my most recently downloaded file. I use it all the time, but its the only stack I do use.