I should explain that I think I must be the most unsophisticated OS user there is. I have my own home network & could give a rip about the increased security & consider it a bit of a PITA. I added W7 to a new system build so I wouldn't need to buy an OS again. My experience so far tho is that W7 is starting to feel like Unix on a Sparc (in the day) with the security system. Experts discourage setting your account to admin and it feels like getting root access. Big deal.
I also live & die on my 5 computers all day long every day running engineering apps. From very interactive to running jobs that can take days of only CPU time to finish.
I always set the Auto-hide task bar option as that is the ultimate in Desktop "cleanliness", in my opinion. In that respect, I see no difference of W7 versus XP or W2K (I never had Vista). I have never understood the need to see (all of the time) what programs are loaded, but reduced. Just moving the mouse to the bottom or where ever you have the task bar parked is all that is needed to see what is loaded. If you have forgotten what is loaded, how important could it be? Or, if you are intending to open a loaded program then you have to go to the task bar anyway and it pops up. No?
There is a subtle new feature that I am warming up to. Perhaps it is in Vista, but the ability to "pin" an app to the task bar is nice. There are certain progs that I like on the desktop, such as Wordpad or Notepad so that I can drag/drop a file from file manager to view it. But that does not apply to all apps. So to keep the desktop from getting too cluttered, those apps may be pinned to the task bar as a more convenient way to find them.
I have a friend that really likes the search for programs & files feature under the Start button. There you can type a few letters of the name of the program that you want. It is very quickly found & highlights at the top of the Start Window. The entire name need not be entered & perhpas only 1 or 2 chars are needed .. this is also a nice feature when I can remember to use it. To me this is 3rd way to keep the desktop clean & organized.
I do have at least 3 ways of accessing programs. Some I am in & out of frequently, others are load & go for a very long time. Others are more interactive, but I don't use very often. So I see new ways of organizing with benefits, but which requires altering some very old habits.
I have had real jobs & worked with MIS security with Windoze and Unix. I still don't see or feel the security advantages or disadvantages of W7. I really have no criticisms of it, except. Except that I do knowingly have security set that several programs such as benchmark software pop up a security window ensuring that you really want to do this. wPrime.exe for instance must be right clicked on & run in administrator mode. Meh.
One bug in a program I have has a GUI, the multiple select ability by holding ctrl key down does not work properly. Only 2 objects can be selected. Selecting a 3rd, deselects one of the others & as such only 2 objects can ever be selected at a time.