Well, there's a matter worth discussing!
Those two articles are very content-filled and make some good points.
I think this thread
is also relevant in this context, as it has some good points about Mac's interface.
IMO, the problem with customization, is how much should be allowed.
I'm not for the windows themes idea, where the "modern" theme only has three different colours and you can't even resize the bar, it has to always take 10% of your screen. It bothers me specially that you cannot iconize the tasks, the buttons have to be very large, so as when you open various apps, the taskbar becomes over-crowded, and you can't find anything.
But I'm also against the way litestep works, because the options are so many, that you get completely lost in the first use. I used blackbox for windows for a few years, and I loved it, but i only started using it because when I found it I was in vacations and had time to spare. It took me two weeks to get everything just as i like it, and even after those two weeks, every week I'd find some option that suited me better.
It is true that when you customize anything, it ends up just the way you want it, and in this matter, i don't agree with Jeff Atwood when he mentions that users often use "color combinations that are known to cause reduced readability of screen text". A user that customizes his desktop to have nice effects, and everything non-standard, only likes having everything nice an shiny, he isn't really worried about productivity.
Joel Spolsky mentions the problem with the resize and replacement of the taskbar. The thing is, some people use it in other places other than the bottom and find it very usefull, and in this forum, you can even find someone that uses the bar taking half of the screen, on the right, and set to auto-hide. (sorry, i couldn't find the link)
I'm for customization, if it respects these criteria:
1) it has to be easy for the user o try out different configurations
2) there has to be a good and easy to restore "default" configuration
3) customization should mainly aim at adapting the program to the user, in order to improve productivity.
My third point has a problem, though. As mentioned by Jeff Atwood, it makes each person's UI different from the next. So, i add a fourth point:
4) the customization options should always be portable
IMO, the way donationcoder's programs work, is the perfect way. Every program should have it's own .ini configuration file, so as you could just grab your .ini, take it somewhere, and use other people's programs just as if they were your own.