That's not really the best question - "Also, do all of you use a desktop enviorment gui? And if so, which and why?" - as it is asked too often, and will sometimes upset some people. A more targeted question would be better... Something like:
I have searched the forums far and wide, found many a thread regarding desktop environments, some excellent debates there were. But when it came down to it, no one mentioned specifics regarding the differences between KDE and twm, and I was hoping to learn. If someone can provide some good unbiased info regarding these, and other, desktop environments, that would be very helpful in my endeavor to use the greatest OS ever developed, thanks" or something like that.
No but really, there are loads of threads with PLENTY of user debate on which is better and why, and if you don't find something that you are really looking for, then by all means, ask.